Involving men and boys as both users and supporters of Family Planning (FP) is now considered essential for optimising maternal and child health outcomes. Evidence on how to engage men and boys to meet FP needs is therefore important.The main objective of this review was to assess the strength of evidence in the area and uncover the effective components and critical process‐ and system‐level characteristics of successful interventions.Connected Papers and hand searches of reference lists.We searched nine electronic databases, seven grey literature databases, organisational websites, and the reference lists of systematic reviews relating to FP. To identify process evaluations and qualitative papers associated with the included experimental studies, we used Experimental and quasi‐experimental studies of behavioural and service‐level interventions involving males aged 10 years or over in low‐ and middle‐income countries to increase uptake of FP methods were included in this review.Methodology was a causal chain analysis involving the development and testing of a logic model of intervention components based on stakeholder consultation and prior research. Qualitative and quantitative data relating to the evaluation studies and interventions were extracted based on the principles of ‘effectiveness‐plus’ reviews. Quantitative analysis was undertaken using r with robust variance estimation (RVE), meta‐analysis and meta‐regression. Qualitative analysis involved ‘best fit’ framework synthesis.k = 265) showed that the included group of interventions had statistically significantly higher odds of improving contraceptive use when compared to comparison groups , but there were substantial variations in the effect sizes of the studies  and 73% was within cluster/study. Multi‐variate meta‐regression revealed several significant intervention delivery characteristics that moderate contraceptive use. These included community‐based educational FP interventions, interventions delivered to women as well as men and interventions delivered by trained facilitators, professionals, or peers in community, home and community, or school settings. None of the eight identified intervention components or 33 combinations of components were significant moderators of effects on contraceptive use. Qualitative analysis highlighted some of the barriers and facilitators of effective models of FP that should be considered in future practice and research.We identified 8885 potentially relevant records and included 127 in the review. Fifty‐nine (46%) of these were randomised trials, the remainder were quasi‐experimental studies with a comparison group. Fifty‐four percent of the included studies were assessed as having a high risk of bias. A meta‐analysis of 72 studies (FP interventions that involve men and boys alongside women and girls are effective in improving uptake and use of contraceptives. The evidence suggests that policy should continue to promote the involvement of men and boys in FP in ways that also promote gender equality. Recommendations for research include the need for evaluations during conflict and disease outbreaks, and evaluation of gender transformative interventions which engage men and boys as contraceptive users and supporters in helping to achieve desired family size, fertility promotion, safe conception, as well as promoting equitable family planning decision‐making for women and girls. Effective types of interventions include community‐based educational programmes targeting males as well as females of all ages, and programmes delivered by professionals, trained facilitators or peers.Engaging men and boys in enhancing gender equality for women and girls as part of family planning programming was highlighted as a key strategy, but this remains an under‐used strategy.1.2This systematic review of intervention evaluation studies is about how to enhance future programming with men and boys to meet needs for family planning for women and men in low‐ and middle‐income countries (LMICs).Addressing unmet needs for family planning is a major challenge in LMICs. Addressing male involvement in family planning is also a challenge, as it is in these countries where men's control over family planning decisionmaking for women and girls is known to be greatest. It is important to involve men and boys in ways that support women's and girls' choices, as well as men's own family planning needs.What is the aim of this systematic review?This review assesses the strength of evidence of involving men and boys as users and supporters of family planning. The review also aims to uncover the effective components and critical process‐ and system‐level characteristics of successful interventions.We used a novel method called causal chain analysis to focus on the content of interventions that may work better than others. This involved developing a picture of important programming components with stakeholders and testing how these components affect the impact of different interventions on family planning outcomes.1.3We included 127 papers which examined the effectiveness of interventions that included men and/or boys in LMICs as programme participants using experimental or quasi‐experimental methods.We also included 23 qualitative studies and process evaluations which reported why and how some programmes might have been effective.The studies were conducted worldwide in LMICs, over half in Africa. A third of the studies were conducted on programmes that made a special effort to engage males. Less than a quarter of the studies addressed gender inequality as part of the programme.1.4When considered together, the interventions included in this review were effective in increasing contraceptive use. The most effective interventions are community‐based educational programmes offered in schools, communities and homes or community facilities, and interventions involving multiple components, delivered by professionals, trained facilitators or peers to both males and females for over seven months. Brief programmes of less than three months are also effective.Added to this, related implementation studies identified the importance of promoting gender‐equitable attitudes and social norms for women and girls among men and women at the individual, wider family, community, health service and societal level as part of family planning programming.Some studies also emphasised structural factors such as the importance of widening women's access to education and labour markets.1.5A wide range of family planning interventions which involve men and boys in LMICs have shown efficacy in increasing contraceptive use.The success of family planning programmes that involve men and boys is most often measured by contraceptive use to the relative neglect of other outcomes, such as met need for family planning, equitable family planning decisionmaking, or gender equality. Our analysis indicates some promising intervention characteristics, which are more effective in promoting contraceptive use than other characteristics.Our qualitative analysis also highlights the under‐used strategy of addressing gender equality attitudes and norms, from the individual to the structural level.The findings of this review will be of interest to programme designers wanting to increase male engagement in family planning in gender‐equitable ways. The review can also help in measuring programme efficacy beyond contraceptive use, to also include gender equality and met family planning needs.1.6The review authors searched for experimental evaluations in August 2020 and ‘connected’ process evaluations and qualitative studies in June 2021.22.1The World Health Organisation estimates that there are approximately 300,000 deaths per year, or 800 every day, among women and girls during childbirth or arising from pregnancy‐related complications, including unsafe abortion. Almost all (94%) of these preventable female deaths occur in low‐ and middle‐income countries (LMICs)  as the bedrock to maternal and child health, economic growth, and the wellbeing of humanity was recognised 25 years ago in the international agreement of the International Conference on Population and Development  in order to ensure decreased unmet need for FP; avoidance of unintended or unwanted pregnancies; birth spacing ; and/or birth limiting . The review focuses on ‘complex’ interventions. While we recognise that some interventions, such as those with only one component, may be considered ‘simple’, following UK Medical Research Council guidelines  interventions for addressing Theoretical approach ;Approach to intervention design ;Materials & procedures (including approach to engaging men and type of contraceptive method);Who provides ;Who receives ;Modes of delivery ;Delivery setting ;Dose and intensity ; andTailoring, modifications, adherence or fidelity.Eligible interventions include those delivered in education, health or community settings aiming to increase capability , opportunity  and motivation  to use FP methods via mass, small or social media information, face‐to‐face communication; health service enhancements; monetary and other incentives; and access to FP methods. The intervention approaches were grouped under the following categories:Interventions that vary on whether and how they address unequal gender norms in FP were also included. The modification of gender norms can be categorised on a continuum from ‘gender‐unequal/neutral’ approaches which reinforce or ignore unequal norms, roles and relations, thereby perpetuating gender‐based discrimination; to ‘gender‐sensitive/specific’ approaches, which do consider gender norms, roles and relations and/or men and women's specific needs or roles but do not seek to change gender inequalities; to ‘gender transformative’ approaches which are inclusive of gender‐sensitive and gender‐specific strategies, but also challenge gender inequalities by transforming harmful gender norms, roles and relations through programmatic strategies that foster progressive changes in power relationships between women and men   (srhr.org) and a systematic review of reviews of male engagement interventions across all SRHR outcomes  two evidence and gap maps What is the nature and extent of experimental evidence on engaging men and boys in FP and what gaps in research knowledge exist?(2)What are the impacts of FP interventions involving men and boys on FP‐related outcomes?(3)What are the effective components of interventions that achieve positive change in intended FP outcomes?(4)What characteristics and combinations of characteristics are associated with positive FP‐related outcomes?(5)Do outcomes vary by context and participant characteristics?(6)Are there any unintended or adverse outcomes?(7)What are the system‐ and process‐level barriers to and facilitators of effective models of FP involving men and boys?The primary aim of this review was to uncover the effective components and characteristics of complex FP interventions involving men and boys in LMICs. In addressing this, we examined the following questions:44.14.1.1As per our protocol ; gender equitable attitudes and behaviours ; FP service use and engagement ; Fertility . Finally, we included met need for FP as a key rights‐based primary outcome.Examples of eligible primary outcomes included: psychosocial determinants of FP such as knowledge, attitudes and social norms; factors relating to relationship quality and discordance such as couple communication and intimate partner violence; attitudes towards FP services including more positive attitudes towards help‐seeking in relation to FP; and community, organisational and structural level outcomes including gender equitable attitudes and support for FP in wider social contexts.Examples of eligible secondary outcomes included: 4.2As we sought to include both quantitative studies and qualitative studies in the review, the search had two phases. The first phase was a comprehensive search for randomised trials and quasi‐experimental studies. The second phase was a search for qualitative studies limited to the specific experimental evaluation studies identified in phase one to be included in the causal‐chain analysis. We used EndNote x9 software to remove duplicates in the search. We used EPPI Reviewer 4 software for data management, screening, extraction, and appraisal and further identification of duplicates with its more sensitive and configurable duplicate identification tool.4.2.11.Searches of academic literature and databases  <August 26, 2020>, Ovid Embase <August 25, 2020>, Scopus <August 26, 2020>, WHO Global Health Library <August 26, 2020>).2.ClinicalTrials.gov Register, ProQuest Dissertation & Thesis A&I, OpenGrey.eu, ELDIS.org) and searching of reports shared by relevant organisation websites . The results were hand searched for potentially relevant articles for the current review. These searches were supplemented with limited searches of the internet using Google <August 10, 2020> and project keywords.Searches of grey literature sources were searched using a selection of key terms on grey literature databases for any materials available to August 20, 2020  . Searches were tested and adjusted as necessary to account for the unique indexing, field codes and truncation for each database.In Supporting Information: Appendix (1)Search for the combination of the terms for population AND family planning AND study design AND LMIC in two databases (PsycInfo and Medline).(2)Scan the first 200 records retrieved in each database to quickly identify studies that appear to meet our eligibility criteria (400 records screened).(3)We used this selection of studies to develop and test a comprehensive list of intervention terms.(4)We then screened a further selection of 200 records in each database to identify a new set of potentially eligible studies. This new set was then used to verify that the newly developed string captured the second set of potentially eligible studies and did not exclude any potentially relevant study.(5)The first set of intervention terms failed to capture one potentially relevant study identified in step 4. The intervention term list was expanded to capture the relevant term (in this case ‘training’) and the process above was repeated once more. All relevant records were identified in the next round. We were therefore satisfied that adding intervention terms improved search specificity without adversely affecting sensitivity.Given the very broad range of potential interventions we did not limit our searches by intervention terms in the initial stages. However, we subsequently developed this search string as follows:We recognise that the strategy combines five search strings, which can result in a less sensitive search. However, given the breadth of the interventions of interest, this was necessary to maximise the specificity of the search and reduce the number of irrelevant records retrieved.4.3To ensure the most effective use of finite time and resources, subsets of the data were used for different review questions  and the connected publications were examined to identify eligible process evaluations and qualitative studies (‘connected papers’). This included investigations of the programme under evaluation conducted in intervention piloting and refinement, simultaneously with delivery, or following implementation assessing aspects of its design and delivery. This led to the identification of 8 qualitative studies and 15 process evaluations for analyses in this review. These studies related to 14 of the 33 male engagement studies.4.3.2Male Engagement code under the Intervention Characteristic domain. This was added because it became clear early in the review process that this was a substantive differentiating factor in some intervention designs. No other content changes were made to the data extraction form.A data extraction form  for the 33 male engagement studies.Study Characteristics and Intervention Characteristics was conducted for 28% [n = 36] of included studies only and dual Risk of Bias Appraisal was conducted for 50% [n = 64] of included studies only. We evaluated the reliability of this approach and concluded that it was acceptable in accordance with accepted standards . Dual extraction of As the characteristics and components of interventions were a central feature of this review, care was taken to extract and code this data according to the a priori defined categories outlined in the initial review logic model full or partial causal‐chain descriptions, whereby authors explain or hypothesise what caused an outcome and under which circumstances;(2)reflections of the original authors on how specific elements of an intervention worked/might have worked; and(3)statements on how specific mediators, moderators, and system‐ and process‐level barriers and facilitators impacted/may have impacted on outcomes.Qualitative data extractions were done for the 23 connected papers and, where reported, the subset of 33 male engagement evaluation studies. Extraction was conducted by one review author in EPPI and checked by a second author. Data constituted verbatim sections of text describing:4.3.3n = 64] of included evaluation studies. We evaluated the reliability of this approach and concluded that it was acceptable in accordance with accepted standards   so robust variance estimation (RVE) was employed to account for dependency in the data. This technique calculates the variance between effect sizes to give a quantifiable standard error for the variable of interest. It has been shown to calculate correct results with a minimum of 20–30 individual studies , with a random effects model. We focused our analysis on contraceptive use because this was the most measured outcome across all studies.4.3.6We used RVE to account for dependencies in the data and to allow us to make use of multiple effect sizes reported in single studies.We coded each study according to intervention components. We used meta‐regression to assess the effectiveness of individual and combined intervention components.4.3.7Of the 127 included studies, 12 study reports did not contain sufficient data to allow calculation of effect size estimates for the primary outcome of our analyses, contraceptive use. When appropriate, we contacted the original authors to request necessary summary data, such as means and standard deviations or standard errors. Where no information was provided, the study was not included in the meta‐analysis and was included in the narrative synthesis only. We were unable to retrieve information for 40 effect sizes across 12 included studies. These studies were included in the review but excluded from the meta‐analysis.4.3.8Q, I2 and Tau2 statistics. Investigation of the source of heterogeneity is addressed in data synthesis section.Heterogeneity was assessed first through visual inspection of forest plots and checking for overlap of confidence intervals and second through the 4.3.9We assessed small study bias (such as publication bias) using a regression test for funnel plot asymmetry Multivariate pairwise meta‐analysis to assess the overall effectiveness of the interventions on reported FP outcomes;(2)Meta‐regression to assess the impact of multiple intervention components and characteristics on FP outcomes; and(3)Narrative synthesis involving the identification of characteristics and components of included interventions and ‘best‐fit’ framework synthesis of connected qualitative studies and process evaluations to identify barriers and facilitators to effective models of FP.We adopted a Causal Chain Analysis (CCA) For each outcome, the following sensitivity analyses was undertaken to assess whether there were potential influences relating to studies that appear to exert an undue influence on findings. We used meta‐regression to assess the impact of:We did not conduct sensitivity analysis on study risk of bias due to the mixture of RCTs and non‐RCTs.4.3.14Geographical regionWho delivered the intervention Intervention dosageIntervention designPopulation included Intervention settingAge of participants Presence or absence of a theory of behaviour changeThe complexity of the logic model means that there were many possible subgroup analyses and meta‐regressions to assess the differential effects in relation to the components of interventions, characteristics of the intervention delivery, population of interest and context. Using robust variance estimates, we conducted analysis for the following:This exploratory analysis used single‐variable, no intercept model and we did meta regression using residual maximum likelihood (REML). The meta‐regression model was a no‐intercept effect size model with dummy codes for each included variable.4.3.15Qualitative data extracted from the 23 connected papers  were analysed using a ‘best‐fit’ framework synthesis approach  and risk of bias tools .Duplicate extraction and appraisal were subject to evaluation by the review team to ensure consistent decision‐making by a single reviewer. To assess inter‐rater agreement and provide a measure of internal validity, we present the kappa statistic, Reliability of data extraction was deemed acceptable in accordance with accepted standards . Time constraints led us to focus our resources of dual extraction and data analysis of intermediate outcome data for a subset of 44 male engagement studies only, 33 of which were included in the meta‐analysis as these included a contraceptive use outcome. These studies were used to answer review Q2 regarding the effectiveness of interventions on intermediate FP outcomes and they were also used as the basis for selecting the 23 connected papers .Finally, in a deviation from our per‐protocol analysis we did not conduct analysis separately for different follow‐up times as planned. Instead, we used RVE to allow us to combine multiple effect sizes on the same outcome from each study while accounting for dependency in the data. We did not conduct separate analysis where the same outcome construct was measured but across multiple time domains, such as through the collection of both post‐test and further follow‐up data.55.15.1.11.Related to a psycho‐social or behavioural FP intervention2.Related to a Randomised Controlled Trial or Quasi‐Experimental Design3.Involved males in intervention delivery4.Conducted in a Low‐ or Middle‐Income Country(ies)Figure n = 2864, 80.5%) ,not related to a psycho‐social or behavioural FP intervention  ,ineligible study design ,did not involve men or boys in intervention delivery ,not conducted in a LMIC .unavailable publication abstract or full text, thus awaiting classification Did not evaluate an intervention Did not evaluate a relevant intervention Ineligible study design, i.e., no comparison group Did not deliver intervention to men or boys Was not conducted in a LMIC   published since 2012. The studies included a total of 491,365 participants. Fifty‐one (40.2%) of the included studies were randomised trials (RCTs), eight (3.1%) were cluster randomised trials (cRCTs) and 68 (53.5%) were quasi‐experimental studies  took place in Africa. Among the most common study sites were Kenya (n = 10), South Africa (n = 7), Nigeria (n = 6). This was followed by Asia (n = 37), with China (n = 12), India (n = 7), Bangladesh (n = 6), and Vietnam (n = 4) the most frequently reported study locations. Around 20% (n = 25) of studies took place in the Americas. Most common study sites were Mexico (n = 7), Brazil (n = 3), Guatemala (n = 3), and Colombia (n = 3).The included studies provide a global scope of reported experimental evaluations of FP programming with men and boys in LMICs. Figure n = 101), contraceptive counselling (n = 21), and maternal and child health programmes (n = 5) , the community (n = 36), healthcare settings (n = 25), homes (n = 6), and some combination of these (n = 21).The studies involved three broad categories in relation to the central design of the intervention—community based educational interventions , but some were delivered to men only (n = 9). The interventions were delivered to adolescents (age 10–19) (n = 39), adults (n = 31) or both (n = 57). Participants received the intervention as individuals (n = 18), couples only (n = 3), groups (n = 45), or via a combination of different modes of delivery (n = 54).Figure n = 38), trained facilitators (n = 31), trained peers (n = 12), mHealth (n = 8), or a combination of these (n = 25). Some mHealth (n = 8) and digital/mass media (n = 2) interventions were delivered remotely with no human contact involved  of studies incorporating this. Other commonly included components were social/peer mentor support  and Communication . Less common were Problem‐Solving and Skills building , subsidisation and incentives , and gender transformative components . While all interventions in the included studies involved men or boys in their delivery, only 35% (n = 44) of included studies substantively incorporated intervention components designed to engage males with through their objectives or tailored delivery for this group.As illustrated in Figure Male Engagement component (N = 44) were those that included substantive engagement of men and boys evidenced either through their objectives or tailoring their practice for males purposefully. Examples of this include:Explicit targeting of husbands for counselling to increase acceptance of female family planning methods  described an intervention comprised of multiple different component types, with 51.9% of described interventions comprising two or three different component types. Noted within evaluations of these complex interventions was the difficulty in parsing the effects of different components and strategies . Most studies n = 116, 1% descriFew studies distinguished whether effects were related to the study's primary or secondary outcomes. Outcomes were judged to be measured at various levels: individual , interpersonal , organisational , and structural .Individual Level Outcomes (n = 127) , and few evaluating Organisational (n = 8) or Structural Outcomes/Impacts (n = 1). A minority of studies examined outcomes at multiple levels, with the most common involving a combination of individual and interpersonal level outcomes. Studies which examined outcomes at higher levels did so simultaneously with the preceding levels of outcomes. All studies that assessed Interpersonal outcomes also assessed Individual level outcomes (n = 38), five studies that assessed Organisation outcomes also assessed Interpersonal outcomes, and the one example assessing structural outcomes assessed outcomes at all preceding levels.Most outcomes assessed by the included studies were n = 127). By far the most common individual‐level outcomes targeted and measured were changes in contraceptive use (n = 72), contraceptive knowledge (n = 52), and changes in attitudes about FP/contraceptives (n = 49). Birth spacing and delay  was assessed chiefly in interventions delivered to adults or groups inclusive of all individuals of reproductive age (n = 36).Most commonly studies targeted and assessed outcomes at the individual level  and Joint decision‐making around FP (n = 12). Perhaps unsurprisingly, interventions attempting to address these were those involving males and females in delivery (n = 10 out of 12). The remaining two studies/interventions were delivered to males exclusively, however, these emphasised building communication skills and the promotion of joint FP decision‐making.Interpersonal level outcomes were assessed in n = 8 studies and chiefly addressed increasing service engagement and accessibility for all, not necessarily specifically for males. A small number of studies, however, did consider enhancing gender equitable beliefs among service providers (n = 3)  reported contraceptive use outcomes, with 48% (n = 21) reporting a heterogeneous mix of outcomes relating to pregnancy, pregnancy timing and desired family size. Forty‐three percent (n = 19) reported attitudes about contraceptives, 36% (n = 16) knowledge about contraceptives, 25% (n = 11) communication about FP, 25% (n = 11) service use and 18% (n = 8) joint FP decision‐making.Most of these 44 studies were conducted in Africa (55%), followed by Asia (36%) and America (9%), with just under half (48%) published since 2012. Approximately half (52%) of the studies were RCTs and the other 48% were quasi experimental studies. Seventy‐seven percent of the 44 studies (n = 26) or contraceptive counselling  focus with a small number  focussed on maternal and child health. Eighty‐seven percent (n = 38) of the studies included interventions that contained between 3 and 6 components, with all but two (95%) including an information and education element. Forty‐five percent (n = 20) included a communication component, 43% (n = 19) a social/peer mentor component, 39% (n = 17) a health service enhancement component and 34% (n = 15) a gender transformative component.Most of the interventions in the included studies had a community‐based educational  were delivered to men and women. This subset was slightly different than all included studies in that it included fewer interventions that targeted adolescents only (only 5% (n = 2) of male engagement studies targeted adolescents only compared with 31% (n = 39) of all included studies). Of male engagement studies more targeted adult populations (43% (n = 19) compared with 24% (n = 31) of all included studies. The studies showed an almost even range of dosage timeframes (ranging from 18% (n = 8) for 7 to 12 months to 15% (n = 11) for >12 months). Half of the interventions were delivered using mixed delivery modes  with the remainder delivered to groups only  or individuals only , couples only  or not specified . In relation to intervention providers, professionals were the most common , followed by trained facilitators  and mixed providers . Four studies (9%) used peers only, and 3 (7%) used MHealth only.The majority of interventions  were published since 2012, with 11 (48%) published between 2015 and 2019. Two studies  predominately received this classification due to under‐reporting of study design and methodology. The majority of quasi‐experimental studies were judged to have a Serious risk of bias (70.6%). Most records were judged to have a Serious risk of bias in multiple domains, however most common Serious judgements related to the treatment of missing data (ROBINS‐I: Domain 5) and potential bias due to confounding (ROBINS‐I: Domain 1).Those quasi‐experimental records identified to have a critical risk of bias  and risk of bias arising from randomisation process (RoB2.0: Domain 1).In total 5.2.2We appraised qualitative studies using Jimenez et al.  critical5.35.3.1k = 265) revealed that the FP interventions had statistically significantly higher odds of improving contraceptive use when compared to comparison groups . The groups who received the FP interventions were one and a third times more likely to experience improved contraceptive use.The meta‐analysis of 72 studies , we investigated I2 further and found that 25% of heterogeneity was between cluster/study and 73% was within cluster/study. We know that the multilevel model contains two variance components (sigma^2_1 and sigma^2_2), for the between‐cluster heterogeneity and the within‐cluster heterogeneity. Therefore, about 25% of the total variance is estimated to be due to between‐cluster heterogeneity, 70% due to within‐cluster heterogeneity, and the remaining 5% are sampling variance. This is an investigation of the total remaining variance after outliers were removed following the process outlined by   on intermediate outcomes measured by the included studies. Identified intermediate outcomes included: attitudes about FP services; attitudes about contraception; knowledge about contraception; FP communication; gender equitable beliefs; joint FP decision‐making; and FP service use. We conducted multivariate pairwise meta‐analysis across 33 studies (k = 226) but urge caution in interpretation as Tipton demonstrates that the Satterthwaite approximation is valid so long as the df is >4 and this is only the case for contraceptive attitudes and contraceptive knowledge in these exploratory analyses, indicating that the analysis is underpowered for outcomes. To allow for estimation of the variance components the Satterthwaite approximation was used to account for two different sample variances where only estimates of the variance are known. The analysis is useful to calculate an approximation to the effective degrees of freedom . Table While the male engagement interventions appear to be improving the outcomes measured ), the results were statistically significant only for contraceptive attitudes  with all 8 identified intervention components added in the model. The test of moderators provides an omnibus test of all components (QM(df = 8) = 27.5844, p = 0.0006) and this indicates that the explained variance across this data is significantly greater than the unexplained variance, overall.Table p = 0.34), ‘subsidised or incentivised contraception’ , ‘health service enhancement’ , problem‐solving and skills  and ‘gender transformative’  components had non‐significant positive effects. The remaining three components, ‘communication’, ‘social/peer support’, and ‘male engagement’ had non‐significant negative effects.As highlighted in Table p = 0.71).We undertook further analysis to assess the combination of components. However, given that there were 33 identified combinations of components in the included studies this exploratory analysis should be interpreted with caution. As illustrated in Table 5.3.3In Table F6,259 = 36.17, p < 0.0001), study design , whether or not there was a behaviour change theory present , who the intervention provider was , dosage , sex of intervention recipients , age of intervention recipients , the setting in which the intervention was delivered , the region in which the intervention was implemented , and the intervention design .Significant differences in effects were associated with year of publication . Interventions with designs primarily focused on contraceptive counselling  did not show significant differences in effect and maternal and child health programmes were not powered to detect trustworthy differences . Dosage was also a significant moderator of effect with intervention durations of <3 months ; 7–12 months ; >12 months  showing statistically significant effects. Interventions with a mid‐range duration of 3–6months did not show significant effects (p = 0.17). Both interventions based on a theory of change  and those not based on a theory of change  were significant moderators of effects on contraceptive use. In relation to the setting in which the intervention was delivered, those delivered in community only , home and community , and schools only  showed statistically significant moderating effects. The intervention provider or who delivers the intervention was also examined and revealed that interventions delivered by trained facilitators only , professionals only , and peers only  were significant.These results suggest that several participant characteristics predicted contraceptive use. Across 72 studies (k = 265), all age categories of intervention recipients were statistically significant moderators: adolescents only ; adults only ; both age groups . Further, the sex of intervention recipients was a significant moderator of effects with interventions delivered to males and females  showing statistically significant effects. Intervention delivered to males only did not show significant effects (p = 0.20).The meta‐regression also highlighted that 5.3.4None of the evaluation studies reported adverse outcomes, although one study  emerged as author‐reported barriers and facilitators of effectiveness and impact in the connected papers. There was no information identified for five of the a priori categories . In relation to external‐level barriers and facilitators, findings related to three of the a priori categories were included in the connected papers . No information was retrieved relating to political and economic climate; legal and historical context; health policies and strategies; conflict; disaster; disease; or climate‐stress.Three additional categories emerged from the thematic analysis that related to individual, interpersonal‐ and community‐level systems: (1) Knowledge about FP among individuals, couples, the wider family, and community; (2) FP communication and decision‐making norms and preferences, which emerged as a sub‐theme of the a priori ‘perceived gender and cultural norms’ category; and (3) Social network influences on decision‐making about family planning, which was closely linked with different modes of FP knowledge. Themes and sub‐themes are highlighted in bold below.socioeconomic factors, including educational attainment and women's employment outside the home  was not mentioned directly in any studies, mentioned in six studies was the strong influence of perceptions of wider family expectations on FP decision‐making .social networks beyond the family on FP uptake and use emerged as important across seven of the connected papers  emerged as potentially important influencing factors. Two additional categories (reach and favourability of contraceptive method) also emerged as relevant.intervention acceptability. Two studies noted the facilitating effects of culturally acceptable interventions , with the trustworthiness, knowledge, and flexibility of providers highlighted as key  and alternative interventions, which may also have included men and boys.Our meta‐analysis of 72 studies and 265 measures of effects of interventions involving men and boys in FP found that, when compared with comparison groups, these interventions exert a moderate, yet statistically significant, positive impact on contraceptive use. The reader should note that this analysis does not compare interventions that involve men and boys While the impact of these interventions on contraceptive use was clear, the causal chain was not. We found that across the range of proximal and distal outcome measures  there were few clear or consistent findings. Individual studies produced a mix of results, using highly heterogeneous interventions, composed of several components, and implemented in a variety of contexts, among diverse populations.within study variability. We therefore sought to uncover the effective characteristics and combinations of characteristics of included interventions. However, such was the variability in relation to outcome measures used, that our analysis of 33 interventions including a male engagement component and contraceptive use outcome was only powered to detect the moderating potential of two intermediate outcome measures (contraceptive attitudes and contraceptive knowledge) and it emerged that only attitudes about contraception had a significant moderating impact on contraceptive use outcomes.Our analysis revealed that the high heterogeneity of effects among included studies was mostly due to The next step in our analysis involved examining the effective components of included studies. Multi‐variate meta‐regression of 72 included studies that reported contraceptive use outcomes indicated that none of the eight intervention components identified were statistically significantly more effective than the others in improving contraceptive use. This is perhaps not surprising given that all interventions included multiple components. We found 33 different combinations of components in use across the 72 studies reporting contraceptive use outcomes and none of the combinations emerged as statistically significantly more effective than the others. When we examined a subset of 33 of the included studies, those involving active engagement of men and boys in FP and the outcome of contraceptive use, we found that the impact of these studies on contraceptive use was not statistically significantly better than those that merely involved men as programme recipients. While at first glance these findings may appear frustratingly inconclusive, and perhaps of little value to programme planners, the findings indicate that a number of different components and combinations of components are possible and effective. This review presents the first collated categorisation of existing interventions involving men and boys in family planning and their components. Given the variety of contexts in which such interventions are implemented, and the recognition that one size does not fit all, this range of possibilities is welcome.The moderator analysis was able to disentangle some of the complexity relating to the characteristics of included interventions, with clear indications emerging regarding promising methods of engaging programme participants and approaches to implementing interventions that involve men and boys. Meta‐regression across 72 studies highlighted the positive impact of community‐based educational FP interventions, delivered to women as well as men, by trained facilitators, professionals, or peers in community, home and community, or school settings. Programmes that primarily involved contraceptive counselling did not statistically significantly moderate effects on contraceptive use and the analysis was not powered to detect the impact of maternal and child health focused programmes. The evidence also supported approaches targeting adolescents or adults alone, as well as those that targeted both age groups. In contrast to the findings of previous research  and alternative interventions, which may also have included men and boys.The analysis suggested that the field of involving men and boys has improved in relation to its capacity to show impact in the last twenty years, with studies published from 2000 onwards emerging as positive moderators of impact. The results also suggest that there may be lessons to learn from programmes implemented in Western and Eastern Africa where positive effects were statistically significantly more pronounced. The reader should note, however, that given the diversity of studies included and the lack of studies in some regions, the analysis was not powered to detect the impact of studies conducted in some regions including South and Central America, Central Asia, and Central Africa. Further, this analysis does not compare interventions that involve men and boys Our qualitative syntheses of findings from 23 connected qualitative and process evaluation papers related to 34 male engagement studies with a contraceptive use outcome revealed several potential barriers and facilitators of effective models of FP involving men and boys. Central here were system‐ and process‐level barriers and facilitators that echoed findings reported in the quantitative synthesis including the importance of promoting positive attitudes about contraceptives, involving trained peers as programme facilitators, and the value of community‐based educational programmes.Reflecting the finding relating to the importance of attitudes about contraceptives as a moderator of contraceptive use, the connected papers reported the facilitative effect of changing attitudes of not only individual men and women, but also those of the wider social network, including family members and peers. Repeatedly, social norms and expectations that encouraged early childbearing, preferences for sons, encouragement of male dominance in decision‐making and stigmatisation of their engagement in FP, were highlighted as barriers. Conversely, and reflective perhaps of the positive effects of peer facilitated and community‐based interventions, the positive attitudes of the wider family, peers and community relating to FP were reported as key facilitators.Though knowledge was not a significant outcome in the quantitative analysis, the crucial importance of accurate knowledge about FP as a facilitator was highlighted in the connected papers, with some studies noting the mediating effect of knowledge of communication about FP. Further, the inclusion of an ‘information and education’ component in almost all included interventions and the moderating effect of interventions focused on a community‐based educational model was reflective of this. In addition, the positive impacts of using trained facilitators or peers and professionals to deliver interventions may reflect the key goal of interventions to impart accurate knowledge about FP.Communication between couples, joint FP decision‐making, and perceptions of gender and cultural norms emerged as important facilitators in the connected papers, although components specifically targeting these outcomes and reports of their measurement appeared much less frequently than attitudinal and behaviour level contraceptive use or pregnancy‐related outcomes. Equally, the focus on pregnancy related outcomes and female contraceptive use suggests that many of the included FP interventions see men as facilitators of women's contraceptive use rather than FP users themselves.Key facilitators of FP use were socioeconomic factors including older life stage, women's employment outside the home, and men's education level.6.1.1All information that was not evidenced  in the included evaluation studies and connected papers was changed from black to grey font to highlight areas for future research to consider.Intervention component headings were changed to reflect more appropriately terms used in the literature. In particular, ‘gender dialogue’ was changed to ‘gender transformative’; information was changed to ‘information and education’, ‘skills‐building and problem‐solving’ were combined, ‘social support’ was changed to ‘social/peer mentor support’, ‘incentivisation’ was changed to ‘subsidisation’ and incentivisation’, ‘Communication’ was changed to ‘Communication about FP’ and ‘male involvement’ was changed to ‘male engagement’. Additionally, ‘free contraceptives’ was added to ‘subsidisation' and incentivisation’ and ‘subsidised or free FP methods’ removed from ‘health service enhancement’.Under intervention characteristics only evidence‐based characteristics after the sub‐headings were left in place. The ‘why’ and ‘tailoring & modifications’ headings were removed. The remaining elements that were not reported or evidenced were changed to grey coloured font.Under potential negative outcomes ‘male resistance to FP leading to covert use and unmet need’ was added and the remaining items which were not reported were changed to grey font.Under process metrics, reach and favourability of contraceptives were added.For the remaining sections, all information not reported was greyed out and information reported left in place.Based on the available evidence and the input collected during our stakeholder meeting, we revised the initial review logic model in the following ways . However, given the slow‐moving nature of publication in this field, the review is timely and, therefore, applicable to those involved in the current development and implementation of FP interventions involving men and boys in FP in LMICs.We followed a pre‐registered peer‐reviewed protocol that was developed in consultation with expert stakeholders and methods experts. A comprehensive search was conducted to identify relevant studies and two reviewers worked independently to select studies using the predetermined eligibility criteria and extract outcome data using a standardised data extraction form. To the best of our knowledge, the evidence presented in this review represents the totality of experimental and quasi‐experimental research from LMICs on the impacts of FP interventions involving men and boys on FP outcomes. We include the broadest range of information available on the nature, extent, and characteristics of experimental evidence in this field from 127 experimental and quasi‐experimental evaluation studies and 23 connected process evaluations and qualitative studies relating to a subset of 33 of the evaluation studies. The large number of studies included in this review meant that data extraction and analysis were more time consuming than expected  had a high risk of bias with serious concerns, while 5 studies (4%) had a critical risk of bias. Fifty‐two studies (41%) were accessed as having a moderate risk of bias with some concerns, and only one study was determined to have a low risk of bias. The majority of the 15 process evaluations and 8 qualitative studies were judged to have moderate risk of bias (78%) while only one study was judged to have a high risk of bias and four studies (17%) to have a low risk of bias.The risk of bias findings should not necessarily be considered indicative of poor study design quality, rather that the majority were conducted in challenging contexts, which affected the proper implementation of the study. The LMIC settings in which these studies were conducted might in part contribute to the need to take pragmatic steps to improve implementation and evaluation. This finding is reminiscent of a previous review of male engagement and sexual and reproductive health and rights interventions published by some of the study authors  and second those that had an active male engagement component and contraceptive use outcomes (33 studies)) reduced the number of studies and associated effect sizes that could be examined as part of the meta‐analysis, limiting our ability to examine some elements of the causal chain in more depth. Further, the use of a sample of associated connected process evaluations and qualitative studies instead of a full search for all relevant papers in the field may have biased our findings.We included all contraception use in the contraceptive use outcome. This included the very small number of studies that included withdrawal as a method of contraception. We used systematic review process methods to minimise bias during the review process. As noted, a deviation from protocol was implemented in relation to dual extraction of data relating to study characteristics, intervention characteristics, and risk of bias assessments. Although this process introduces the possibility of bias, we are confident that the reliability of this approach is in line with accepted standards , which are often done without comparison groups. Given the expense involved in conducting controlled experiments, and the fact that this study focused on low resource settings, this could be considered a limitation. However, from the perspective of methodological rigour, RCTs and quasi‐experimental studies with a comparison group ensure assessment of the effectiveness of interventions.While information was available in most studies to calculate effect sizes, this was not always the case. The study team contacted authors to request additional data to facilitate this, however, no authors responded with the required information. It is possible that this resulted in biased findings. Also, we did not extract data on the urban/rural breakdown, a limitation of our review, considering that there was some evidence that this distinction is important.Moderator analyses are exploratory in nature and should always be interpreted with caution  to overall effects, it is extremely difficult to understand the individual and combined impact of different components using classical experimental methods. Further research should therefore consider alternative methods that are capable of uncovering the individual and combined effects of intervention components. One such approach is the Multiphase Optimisation Strategy (MOST) Collins, , which iThe legacy of a focus on population control and global patriarchal norms has undeniably influenced the state of current FP interventions, which centre around birth limiting and birth spacing and women's central role as contraceptive users. While we intended to study unmet FP need, we found that the most common included outcome across all studies was contraceptive use and unmet family planning need was rarely studied. Areas and topics of interest for future FP interventions should include engaging men as contraceptive users, supporters, and agents in helping to achieve desired family size but also in fertility promotion interventions, safe conception interventions , and family planning decision making in non‐heterosexual relationships.Similarly, all interventions included in this review adhered to binary and cis‐normative concepts of gender identity and sexuality. Family planning remains a pertinent issue for those identifying as LGBTQI+, with authors noting that even those who have transitioned socially or hormonally are in need of support to ensure they can achieve their desired family size  with support from UK Aid from the UK government. The funding body had no role in the study design, or decision to publish findings. The authors have no conflicts of interest to declare.The preliminary timeframe for submission of the completed review was one year following protocol publication. This was delayed by two months (the protocol was published in January 2021 and the completed review submitted in March 2022).The authors seek support to update the results of this review in line with emerging evidence in the field. We anticipate that the need for the next update will be considered in 5 years.Deviations from the review protocol are presented in Section None.Supporting information.Click here for additional data file.


While standard chemotherapy is able to target rapidly proliferating immature blasts, it fails to eradicate slowly proliferating Leukemic Stem Cells. Therefore, new therapeutic strategies that efficiently target LSCs are urgently needed. Recent studies suggest that LSCs have particular metabolic vulnerabilities, which would open the possibility of a therapeutic window with limited off‐target effects on the normal hematopoietic system. In this issue of EMBO Molecular Medicine, So and colleagues investigate the mechanism of action of AG636, a new potent inhibitor of  et al (in this issue of EMBO Mol Med) that investigates the mechanism of action of AG636, a new potent inhibitor of de novo pyrimidine synthesis, in the context of acute myeloid leukemia. E. Donato and A. Trumpp discuss the study by So  AML is the most aggressive blood cancer with a 5‐year survival rate lower than 20% for patients older than 65 years. While the majority of patients initially reach complete remission after standard chemotherapy, the rate of mortality remains very high due to recurrent disease. The formation of AML relapse is ascribed to the persistence of chemotherapy‐resistant LSCs with long‐term self‐renewal activity able to regenerate the disease. Previous studies have demonstrated that AMLs show a hierarchical organization with quiescent/low cycling LSCs at the top of the tree giving rise to fast proliferating immature myeloid blasts unable to generate terminally differentiated mature cells , an essential enzyme localized in the mitochondrial inner membrane and catalyzing the fourth step of the et al, de novo pyrimidine synthesis is not limited to MLL rearranged AMLs, since also AML1‐ETO or IDH1R132H/DNMT3AR882H/NrasG12D mouse models were susceptible to DHODH inhibition. Even though AG636 treatment was associated with reduction of normal B cells, myeloid and megakaryocyte‐erythroid progenitors as well as LT‐HSCs, this effect was transient and normal hematopoiesis returned to baseline after drug discontinuation. Transcriptomic analyses of enriched LSCs (cKithigh CD11blow) identify genes associated with protein synthesis as strongly deregulated after DHODH inhibition. This observation was further validated by polysome profiling and L‐Azidohomoalanine incorporation, functionally demonstrating that AG636 treatment leads to the inhibition of the protein translation machinery. By chromatin accessibility analysis on enriched LSCs (cKithigh CD11blow) and data mining using publically available datasets, the authors identified YY1 as a potential transcriptional regulator of genes controlling protein translation. This observation was particularly interesting since YY1 is post‐translationally modified by the addition of O‐GlcNAc: a post‐translational modification dependent on pyrimidine biosynthesis. The crucial role of O‐GlcNAc modification was confirmed by rescue experiments with an inhibitor of O‐GlcNAcase (PUGNAc). Thus, de novo pyrimidine synthesis inhibition by AG636 is altering YY1 stability by preventing O‐GlcNAc modification with consequent downregulation of its target genes (Fig In this issue of EMBO Molecular Medicine, So and colleagues report findings from a preclinical study assessing the novel potent DHODH inhibitor AG636 (So Finally, by performing CRISPR‐Cas9 KO screens using a focused library of epigenetic regulators, the authors identified CDK5 and members of the INO80 chromatin remodeling complex as sensitizer to DHODH inhibition. Transcriptomic analysis of CDK5 knockout cells treated with AG636 revealed numerous genes involved in OxPHOS and the Electron Transport Chain as being strongly downregulated, suggesting that the synthetic lethality could be explained by a dual synergistic attack on mitochondria Fig .de novo pyrimidine synthesis for survival and cell fate decision, respectively. Interestingly, in LSCs, pyrimidine starvation is controlling protein modification and stability of key transcription regulators and YY1 was identified as a novel regulator of protein translation in AML. Finally, synthetic lethality was observed when DHODH inhibition was concomitant with depletion of CDK5. Indeed, the authors showed for the first time that CDK5 regulates the expression of ETC complex I and II components (Fig et al will certainly guide future investigations dissecting the full spectrum of the roles of pyrimidines in AML.In summary, So and colleagues shed new light on the mechanism of action of DHODH inhibition, further proving LSC and blasts dependency on


Drosophila seminal protein ‘sex peptide’ (SP) is perhaps the most widely cited example of a trait that appears to harm females while benefitting males. Transferred in the ejaculate by males during mating, SP triggers profound and wide‐ranging changes in female behaviour and physiology. Early studies reported that the transfer of SP enhances male fitness while depressing female fitness, providing the foundations for the widespread view that SP has evolved to manipulate females for male benefit. Here, we argue that this view is (i) a simplification of a wider body of contradictory empirical research, (ii) narrow with respect to theory describing the origin and maintenance of sexually selected traits, and (iii) hard to reconcile with what we know of the evolutionary history of SP's effects on females. We begin by charting the history of thought regarding SP, both at proximate  and ultimate (its fitness consequences and evolutionary history) levels, reviewing how studies of SP were central to the development of the field of sexual conflict. We describe a prevailing paradigm for SP's evolution: that SP originated and continues to evolve to manipulate females for male benefit. In contrast to this view, we argue on three grounds that the weight of evidence does not support the view that receipt of SP decreases female fitness: (i) results from studies of SP's impact on female fitness are mixed and more often neutral or positive, with fitness costs emerging only under nutritional extremes; (ii) whether costs from SP are appreciable in wild‐living populations remains untested; and (iii) recently described confounds in genetic manipulations of SP raise the possibility that measures of the costs and benefits of SP have been distorted. Beyond SP's fitness effects, comparative and genetic data are also difficult to square with the idea that females suffer fitness costs from SP. Instead, these data – from functional and evolutionary genetics and the neural circuitry of female responses to SP – suggest an evolutionary history involving the evolution of a dedicated SP‐sensing apparatus in the female reproductive tract that is likely to have evolved because it benefits females, rather than harms them. We end by exploring theory and evidence that SP benefits females by functioning as a signal of male quality or of sperm receipt and storage (or both). The expanded view of the evolution of SP that we outline recognises the context‐dependent and fluctuating roles played by both cooperative and antagonistic selection in the origin and maintenance of reproductive traits.A central paradigm in evolutionary biology is that the fundamental divergence in the fitness interests of the sexes  can lead to both the evolution of sex‐specific traits that reduce fitness for individuals of the opposite sex, and sexually antagonistic coevolution between the sexes. However, clear examples of traits that evolved in this way – where a single trait in one sex demonstrably depresses the fitness of members of the opposite sex, resulting in antagonistic coevolution – are rare. The  Ivice versa) via sperm competition  and cryptic female choice  or indirect (e.g. ‘good genes’) benefits that females accrue from mating with preferred males, resulting in the coevolution of female preferences and preferred male traits D. melanogaster i) seminal fluid was the basis of the costs of mating incurred by females; and (ii) SP triggered the core female post‐mating responses. It was at this time that a gene‐knockdown line for Sex Peptide became available , SPR is present in species across the Lophotrochozoa and Ecdysozoa  that have wide‐ranging effects on physiology and behaviour across taxa  might elevate costs for males, such that only high‐quality males can transfer sufficiently stimulating quantities of SP. As described above, females might then gain by tailoring reproductive investment and decisions in relation to information on male quality from SP.From these starting points, several evolutionary trajectories are possible. First, selection might act to the mutual benefit of males and females. Whenever receiver responses benefit both signaller and receiver, selection should favour features that promote the efficacy with which the cue or signal elicits the favourable response [‘efficacy selection’ D. melanogaster, beginning with the discovery that females experience costs from mating that are independent of offspring production  comes from a series of laboratory studies in et al., et al., Although a negative effect of SP on female lifespan has since been replicated in a study that did not measure reproduction et al., D. melanogaster in natural populations, compared with laboratory conditions. Adult survival in Drosophila has been estimated to be as low as 45–85% per day in capture–recapture experiments, suggesting an adult life expectancy of 1.3–6.2 days in field conditions et al., et al., Can we be confident that the fitness effects attributed to SP are in fact caused by SP? A recent study has revealed an unexpected role for SP within ejaculates: SP is critical to the formation and dissipation of ‘microcarriers’, which are lipid‐based structures that provide storage, delivery, and dispersal machinery for several seminal proteins transferred to females , compared with wild‐type females i) the SPR gene long pre‐dates SP, and (ii) SPR has another class of ancient, conserved ligands (MIPs) to which it binds SPR‐expressing, SP‐sensing neurons in the uterus near the sperm storage organ ducts  are induced by a set of two bilateral clusters of three SPR pre‐dates SP, but specifically that SPR expression in reproductive tract neurons pre‐dates SP. However, a recent study contradicts this prediction. Instead, it suggests that SPR expression in the reproductive tract is a derived trait, and that SP evolved before robust expression of SPR in the female reproductive tract  do not show the key post‐mating response of reduced receptivity when injected with SP D. melanogaster and its close relatives includes a QRY motif that replaces the well‐conserved DRY sequence found in many invertebrate G‐protein‐coupled receptors et al., Drosophila species appears to co‐vary with the SP gene; for example, D. mojavensis, which lacks SP, does not produce microcarriers, while D. pseudoobscura and D. persimilis, which have SP, do  expressed elsewhere in the female. Consistent with this hypothesis, some female post‐mating responses to SP appear to be independent of SPR (Haussmann (3)Drosophila phylogeny is consistent with this process. Following the evolution of SP transfer, the subsequent evolution of SPR expression in the female reproductive tract may have enhanced female ability to detect SP and to use its detection to switch to a reproductive state more quickly and accurately. This puts mechanistic meat on the bones of the long‐standing idea that females could use SP  as a cue of successful mating et al., Females might use SP as a cue or signal of sperm receipt or storage, but another, non‐mutually exclusive function is possible: SP may signal male quality or condition. SP might have been ancestrally condition dependent, before the evolution of any signalling function  and benefit from doing so. If SP functions as a signal of sperm storage alone, then females must also benefit from responding to SP. However, in this case the quantity of SP transferred may or may not reflect male quality, and females may either show a threshold response to SP, initiating post‐mating responses once a minimum quantity is detected, or a dose‐dependent response. A dose‐dependent response to SP as a sperm storage signal could occur if SP transfer is tightly linked to sperm number, and females benefit from tailoring the duration or total stimulation of post‐mating responses to the number of sperm received (see Section (a)et al., et al., D. melanogaster populations vary in SP hydroxylation  of hydroxyproline and an isoleucine residue Drosophila melanogaster females can eject sperm after mating  that a female's previous mate can influence the phenotype of offspring sired by subsequent mates  from a second male  or suffer reduced lifespan. This depression in female reproduction or lifespan would make SP look like a harmful trait, as in Wigby & Chapman  The idea that SP acts as a signal of male condition raises questions about how honesty is maintained, female information processing, and the interpretation of previous experimental evolution studies.(i)Drosophila melanogaster males strategically alter the quantity of sperm and SFPs produced and transferred in response to cues of sperm competition  at higher male densities After a first mating, a female can attribute the quantity of SP received to her mate. However, after several matings a female will retain SP from multiple males. Indeed, SP transferred by one male can bind to the sperm of a rival within the female storage organs et al., et al. , impose greater survival costs on their female partners, and induce greater stimulation of egg production and transcriptional responses in their partners D. melanogaster  variation in SP transfer might covary with male condition. Females could use this information about male condition to guide their reproductive investment decisions  in order to capitalise on the good gene (or direct) benefits of mating with high‐quality males. There is some evidence that SP meets the criteria for condition‐dependent signals: females can benefit from SP receipt, SP transfer covaries with male condition, and females appear to tailor some parts of their reproductive effort to the amount of SP they receive. However, the data are inconclusive and more study is required. We need to be able to distinguish the effects of SP from the myriad other ejaculate components, in terms of both the degree of condition dependence it exhibits and its specific contribution to quantitative variation in female post‐mating responses.via sexually antagonistic coevolution or mutually beneficial ritualisation; and even transitioned from manipulation to cooperation or vice versa. As long as male and female interests are not perfectly aligned, conflict will inevitably persist, perhaps manifesting as continued low‐level exploitation within a broadly honest, established signalling system  represents a false dichotomy: both processes can have made different contributions at different points in SP's evolutionary history, their relative influence shifting through time and the fitness effects of SP changing with the ecological context.A narrow focus on sexual conflict over SP's effects on females neglects more expansive frameworks that recognise the contribution of both antagonistic and cooperative processes to the evolution of SP (and reproductive traits more broadly). SP's effects on females may have originated as a cue, a signal, or through sensory exploitation; subsequently evolved SPR expression in the female reproductive tract allow SP detection for the first time, or did it enhance a pre‐existing female ability to detect SP? If SP transfer is condition dependent, was it always so or did condition dependence evolve following female ability to detect SP within the reproductive tract? Did the ability of SP to bind sperm and therefore remain detectable over prolonged periods pre‐date female ability to detect SP in the reproductive tract? Which party controls the cleavage of SP from the surface of sperm? Answering these questions will help to resolve the evolutionary assembly of the SP–SPR system, a focal point for understanding the evolution of reproductive interactions.A more expansive view that considers these different forces illuminates questions that need answers to understand SP's evolution. Did the evolution of et al., Drosophila offer huge promise for establishing SP as a textbook animal signalling study system.Our discussion of the conditions under which SP could function as a signal, either of male quality or of mating and sperm storage, represents an approach to treating molecular signals as animal signals. Molecular signals raise new questions about signal evolution. For one, a molecular signal like SP does not act through the receiver sensory modalities  traditionally associated with signals; interestingly, the SP‐sensing neurons in the female reproductive tract share transcriptomic similarities with proprioceptive neurons (Rezával Helicoverpa armigera (Kiran et al., Helicoverpa zea (Kingan, Thomas‐Laemont & Raina, Aedes aegypti (Duvall et al., Drosophila quirk. But the fundamental relationship between male seminal fluid and the female post‐mating response is apparently ubiquitous among insects. These observations raise two fundamental questions: why is male influence over female post‐mating behaviour so common? And why are there so many lineage‐specific molecules by which males influence it? Given the ever‐increasing depth with which the system is understood, the study of SP in Drosophila may be our most powerful tool for answering these questions.While the SP–SPR system appears confined to a subset of drosophilids, a substantial increase in egg‐laying and a reduction in sexual receptivity following receipt of accessory gland products are widespread phenomena among insect species (reviewed in Chen,


The coronavirus disease 2019 (COVID‐19) pandemic has entered its endemic phase and we observe significantly declining infection fatality rates due to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). On this background, it is crucial but challenging to define current and future vaccine policy in a population with a high immunity against SARS‐CoV‐2 conferred by previous infections and/or vaccinations. Vaccine policy must consider the magnitude of the risks conferred by new infection(s) with current and evolving SARS‐CoV‐2 variants, how these risks vary in different groups of individuals, how to balance these risks against the apparently small, but existent, risks of harms of vaccination, and the cost–benefit of different options. More evidence from randomized controlled trials and continuously accumulating national health data is required to inform shared decision‐making with people who consider vaccination options. Vaccine policy makers should cautiously weight what vaccination schedules are needed, and refrain from urging frequent vaccine boosters unless supported by sufficient evidence. Omicron infection fatality rate (IFR) until mid‐March 2022 was estimated to be only 6.2 : 5.1–7.5) per 100,000 infections among apparently healthy people 17–72 years old.In populations with substantial prior exposure to SARS‐CoV‐2, reinfections (the vast majority occurring in the Omicron waves) had less than a quarter of the hospitalization risk and one‐tenth the mortality risk compared with the primary infections, for example, in Vojvodina, Serbia, only 1% of reinfections required hospitalization and the case fatality for reinfections was only 0.15%.3National data from Portugal including a population aged 12 years and older with an 82% coverage of the third vaccine dose against SARS‐CoV‐2 were used to compare groups of previously uninfected individuals versus groups with one documented infection in terms of infection rates with SARS‐CoV‐2 during the Omicron BA.4/BA.5 wave between 1 June and 4 July 2022.Characteristics of immunity against SARS‐CoV‐2 on a national level may also be of interest for offering some hints on the relative protection offered by prior infection versus vaccination. For example, South Africa has had a low vaccination uptake in 2021 but high prevalence of previously infected individuals when considering seroprevalence data.4n = 27,876) and those who had only received three vaccine doses .There are currently no data on vaccine efficacies for the fourth dose (referring to mRNA vaccines) with reference to the prevention of SARS‐CoV‐2 infections from large RCTs, so we have to rely on observational studies. These studies have been largely conducted in Israel, as national health authorities in this country recommended a fourth dose of the BioNTech‐Pfizer vaccine (BNT162b2) for all individuals aged 60 years and older at the beginning of 2022, along with recommendations for this booster in immunosuppressed individuals and those at high risk of exposure .n = 12,262 for each group) were followed up for 7–60 days from January to May 2022.In contrast to these healthcare professionals with an extremely low risk of severe COVID‐19, the respective risk may be much higher in very old populations with frailty and comorbidities.A critical and serious limitation of the major studies in the general population on the efficacy of the fourth vaccine dose against SARS‐CoV‐2 is the almost universal exclusion of individuals with previous infections.5The lower the underlying risk for severe COVID‐19 outcomes, the more careful should be the risk to benefit analyses of the vaccines, in particular if some adverse vaccine effects such as myocarditis are relatively frequent in low‐risk populations as, for example, male adolescents and young adults.6Healthcare costs of mass vaccination and the possibility that overwhelming attention to SARS‐CoV‐2 could reduce resources for and adherence to other preventive measures such as uptake of other vaccines or health examinations might also be considered. A major challenge with factoring cost properly in such analyses is that many countries and conglomerates thereof, for example, the European Union, have made ludicrous massive contracts with vaccine manufacturers, with the lion's share pertaining to Pfizer for its mRNA vaccine and boosters. From a deal with the European Union, covering up to 1.8 billion vaccine doses, Pfizer/BioNTech may have made profits of up to 29.5 billion US Dollars.Previous cost‐effectiveness analyses on measures against SARS‐CoV‐2 were generally based on overestimated IFR and may thus have been too optimistic.For illustrative purposes, we used the IFR from Denmark at the beginning of 2022 and calculated the NNTs and costs to prevent one COVID‐19 death according to various different efficacies and costs for an extra booster dose (see Table Although we present only a rough estimate and not an accurate cost‐effectiveness analysis, such considerations are required for the discussion on the justification of any measures against COVID‐19.7Both COVID‐19 vaccines and the virus will probably evolve in the future. The evolution of the virus towards new variants is largely unpredictable. The inherent fatality risk of new variants and their immune evasion against immunity conferred by prior infection and/or vaccination will be important to monitor and consider, as they may markedly change the balance in favour or against specific vaccination schedules. Therefore, genomic, epidemiological and clinical impact surveillance for SARS‐CoV‐2 will remain important in the endemic phase, in a similar fashion as it has been for influenza. There is even more uncertainty about the future role of different vaccines. COVID‐19 vaccine development has an active research agenda. New vaccines may emerge, including vaccines that have better effectiveness at blocking infection and transmission, features where the currently widely used COVID‐19 vaccines perform poorly at.In the meanwhile, there is an urgent need to address several research questions that are required to inform current vaccine policy. Ideally, these questions should be addressed by large RCTs and access to continuously accumulating national health data: Does the general population with hybrid immunity benefit from additional vaccine booster doses? Does prevention of positive SARS‐CoV‐2 PCR tests by vaccination justify their use even if there is no meaningful effect on severe COVID‐19 or mortality in terms of absolute numbers of events averted? How should one balance COVID‐19 vaccine policy in the context of other vaccine policies or public health measures in view of limited resources and the interaction of each measure? What is the cost‐effectiveness of different strategies? Cost‐effectiveness needs to consider also the possibility of wasted vaccines that are paid pre‐emptively by governmental authorities, but are then not used in the shifting sand evolution of COVID‐19. Arrangements of authorities with vaccine manufacturers should not include pledging upfront payment for an unrealistic number of doses. Transparency, accountability and protection from conflicts of interest are totally essential in the interplay between manufacturers and government officers, scientific advisors and other stakeholders who shape perceptions, expectations and public opinion pressure about COVID‐19 vaccines. Many other important research questions need to be answered to inform vaccine policies that are currently based on limited evidence. The continued lack of rigorous, randomized evidence raises serious concerns.The performance of timely, large‐scale RCTs for addressing the effectiveness and harms of booster strategies is clearly feasible and even indispensable. Contrary to the argument that large RCTs take very long to complete, during the pandemic large RCTs like RECOVERY and SOLIDARITY provided conclusive evidence on the effectiveness of several treatments within 3–6 months of being launched.8While rigorous evidence remains unavailable, authorities struggle in their decision‐making resulting in heterogenous national recommendations regarding the fourth vaccine dose in the general population (see Table With a broader view, during the endemic phase of COVID‐19, we have to consider the possibility that mass vaccination with frequent boosters may no longer be necessary for the majority of the population but only for certain risk groups, for example, the elderly and in particular long‐term care residents. It is conceivable that SARS‐CoV‐2 infections may soon follow a similar pattern as the other endemic human coronaviruses, with a first, usually mild infection in childhood and thereafter frequent but also generally mild infections in adulthood.The authors report no conflicts of interest.There was no specific funding for this work.All authors have substantially contributed to the design and writing of this manuscript.


TP53 loss and/or TP53 mutation and by refractoriness to purine‐analogue based treatment (no remission or remission under 6 months in duration), respectively  was defined by the presence of ectively . The advectively , samplesFrom a clinical perspective, high-risk CLL may hitherto best be defined by refractoriness, non‐durable response or intolerance towards the two drug classes that have become most relevant for CLL treatment: covalent BTK inhibitors (BTKi) such as ibrutinib and acalabrutinib and BCL2 inhibitors (BCL2i) such as venetoclax . HoweverTP53 disruption has yet been conclusively clarified in the setting of BTKi and BCL2i based treatment. This clearly illustrates how difficult it will be to develop multivariate prognostic models that take genetic, epigenetic, transcriptional, phenotypic and clinical parameters into account and permit an individualised treatment recommendation for every CLL patient that considers clinical benefit as well as costs.Validating the prognostic or predictive impact of potential biomarkers has been complicated by a growing number of targeted compounds, immunotherapeutic agents and products for adoptive cell therapy that need to be tested in prospective clinical trials. The plethora of options for new monotherapies and combination therapies to be evaluated requires large numbers of CLL patients to be enrolled on clinical trials. The distribution of patients across a multitude of therapeutic options makes it difficult to reach the statistical power necessary to validate the impact of each potential biomarker for each individual treatment approach. In keeping with this notion, not even the prognostic impact of The scope of the Research Topic “Biology and Treatment of High‐risk CLL” is to provide a state-of-the-art overview of the pathobiological mechanisms underlying high‐risk CLL, to list and critically evaluate biomarkers that have been associated with a high‐risk disease character and to outline the implications of these biomarkers on response to different treatment approaches including chemoimmunotherapy, targeted therapy and cellular immunotherapy. Another issue discussed within the Research Topic is Richter transformation, which is defined as the development of a high‐grade lymphoma in patients with a previous or concurrent diagnosis of CLL or small lymphocytic lymphoma (SLL) and frequently associated with a dismal prognosis.Kwok and Wu. discuss prognostically relevant biologic alterations in CLL observed at the genetic, transcriptional, epigenetic and microenvironmental level. In case respective data was available, alterations are regarded as dynamic processes throughout which the tumor can evolve towards therapeutic resistance and progression. Building up on this, the authors create a future vision how multidimensional tumor heterogeneity and tumor growth dynamics could become parameters in a prognostic model allowing more personalised treatment choices.The Research Topic is opened by a review article in which TP53 alteration serving as a defining criterion of high‐risk CLL and as established predictor for chemoresistance .After this introductory review, three articles focus on sistance . Soussi Chatzikonstantinou et al. present available data on the prognostic and potentially predictive value of karyotype complexity in CLL and discuss the impact of low, intermediate and high genomic complexity against the background of concomitant high-risk biologic features. Subsequently, Zavacka and Plevova. shed light on chromothripsis defined as a genomic event by which a single chromosome or a limited number of chromosomes are shattered into pieces and reassembled in an error-prone process. The authors discuss the potentially underlying biological causes for this event and review the impact of chromothripsis on CLL disease progression and treatment response. Then, Nguyen-Khac. addresses the role of MYC rearrangements in CLL with a focus on concurrent loss of the TP53 gene locus, a constellation termed “double‐hit CLL”. This latter topic is backed up by an original research article by Ondrouskova et al. describing the frequency of MYC‐rearranged CLL in a cohort of 303 cases from a single center and dissecting the types of the genomic alteration responsible for MYC rearrangement in an extended cohort.In the next section of the Research Topic, three additional poor prognostic biomarkers identified at the genetic level are highlighted. First, Gerousi et al. explain the concept of B‐cell receptor stereotypy in CLL and summarise data on CLL subsets defined by stereotyped B‐cell receptors and associated with an aggressive clinical course. In a complementary perspective article, Nicolo et al. put emphasis on the fact that alterations in the B‐cell receptor immunoglobulin light chain can also drive the development of high‐risk CLL. Afterwards, Edelmann. elucidates the impact of NOTCH1 mutations and further alterations associated with de-regulated NOTCH1 signaling.The Research Topic then focusses on two cell signaling pathways shown to influence prognosis. First, B‐cell receptor signaling is highlighted as a key survival pathway for CLL cells. Condoluci and Rossi. address the issue of Richter transformation by giving insight into its pathobiology and summarizing data on potential treatment options recently evaluated in clinical trials.Richter transformation is a dreaded complication of CLL evolution with an aggressive clinical course and no established treatment options. Straten et al. select TP53 alterations, Del(11q), genomic complexity, unmutated IGHV mutation status, stereotyped B‐cell receptor subsets, NOTCH1 mutation and BIRC3 mutation from the list of poor prognostic factors in CLL and discuss their clinical impact based on available data from clinical trials testing chemotherapy, chemoimmunotherapy, anti‐CD20 treatment, BTK inhibition, BCL2 inhibition, Pi3K inhibition and/or allogeneic stem cell transplantation. The authors also comment on the next generation kinase inhibitors zanubrutinib, pirtobrutinib and duvelisib, the anti‐CD20 monoclonal antibody ublituximab and on CAR-T-cell and CAR‐NK cell therapeutic approaches. To explain the role of allogeneic stem cell transplantation and CAR T‐cell therapy in more detail, Barbanti et al. add a review article focussing on the use of these cellular approaches for the treatment of high‐risk CLL and Richter transformation.The last section of the Research Topic is dedicated to treatment of high‐risk CLL. To systematically approach the question how high‐risk CLL behaves under various treatment approaches, Edelmann, Malcikova et Riches propose a new definition of high‐risk CLL taking disease intrinsic risk factors as well as additional elements with an influence on overall survival into account.In a concluding Opinion Article, All authors made a substantial, direct and intellectual contribution to the conceptual design of the Research Topic. JE wrote the Editorial. All authors contributed to the article and approved the submitted version. Eugen Tausch, Jitka Malcikova and John Riches contributed equally to the conceptual design of the Research Topic." in Author contributions.


We use pulsed Electron Paramagnetic Resonance (EPR) techniques to characterise and separately address the individual electron spin qubits; CuII, Cr7Ni ring and a nitroxide, to determine the strength of the inter‐qubit dipolar interaction. Orientation selective Relaxation‐Induced Dipolar Modulation Enhancement (os‐RIDME) detecting across the CuII spectrum revealed a strongly correlated CuII‐Cr7Ni ring relationship; detecting on the nitroxide resonance measured both the nitroxide and CuII or nitroxide and Cr7Ni ring correlations, with switchability of the interaction based on differing relaxation dynamics, indicating a handle for implementing EPR‐based quantum information processing (QIP) algorithms.Dipolar coupled multi‐spin systems have the potential to be used as molecular qubits. Herein we report the synthesis of a molecular multi‐qubit model system with three individually addressable, weakly interacting, spin  Systems with weak dipolar interactions have the potential to be used for molecular quantum computing. Orientation selective pulsed EPR was used to model the conformational flexibility of a molecular multi‐qubit model system. Spectrally addressable centres allowed for the individual manipulation of each spin qubit, while differing relaxation dynamics resulted in a proposed handle for the implementation of quantum algorithms. Selective excitation of the xyg position yields strong orientation selectivity, resulting in higher relative intensity of the higher frequency contributions to the trace , and is described in detail . An iterative least squares fitting routine, as reported previously,g‐matrices in space. The presence of several oscillations in the experimental time traces indicate that a limited range of dipolar interactions and thus conformational distributions are present for these two centres, with the predicted relative orientation of the Cr7Ni ring gz component, in the frame of the CuIIg‐tensor, corroborating single‐crystal studies of Cr7Ni ring g‐tensor orientation7Ni ring gz component of the top 1/3of fits are plotted relative to the DFT optimised model  a five‐pulse dead‐time free sequenceTmix optimised at 3 K for isolating the nitroxide‐Cr7Ni ring interaction resulted in a much faster dipolar oscillation due to the shorter through space spin‐spin distance of ca. 1.33 nm; this is consistent with the single crystal XRD data (1.35 nm) of the two‐spin intermediate complex . This pairwise interaction could be confidently isolated up to temperatures of 5 K and for a Tmix on the order of 1 ms. As Tmix is increased, relaxation of the CuII spin becomes sufficient to also modulate the detection spin echo. It is assumed that the dipolar oscillations seen at 5 K with variable Tmix are dominated by the individual pairwise interactions rather than by MSEs, therefore best fitting simulations of the pairwise interactions at 3 K and 6 K were simply scaled and summed based on the % of CuIIT1 that is accessible within the chosen Tmix in order to fit the data . The best fitting centres of spin density at both 3 K (yellow) and 6 K (orange) are shown relative to the DFT model . A self‐consistent model containing a global multi‐frequency fit of orientation parameters determined from both DEER and RIDME data gives an indication of the restricted conformational flexibility of the molecule relative to a fixed position of the Cr7Ni ring  detecting on the nitroxide spin, with  GHz deteT1 of the constituent molecular spins, highlights the Cr7Ni ring as an excellent ancillary qubit for mimicking the effect of the environment in inducing decoherence. If an entangled state of the Cr7Ni ring with one, or both, of the other spin qubits is generated, the comparatively fast relaxation of the Cr7Ni ring would lead to a controlled decoherence in the state of the others. For instance, decoherence of the two “logical” qubits can be simulated by a fast single qubit rotation of the Cr7Ni ring, followed by a three qubit Toffoli gate,7Ni ring spin conditioned by the state of the “logical” qubits, which is permitted by dipolar interactions. Upon relaxation of the Cr7Ni ring, the state of the other spin qubits coincides with the one in which decoherence has acted for a time controlled by the angle of the initial rotation of the Cr7Ni ring spin . Of particular interest is the study of decoherence on an entangled state of the CuII and nitroxide spin qubits. The two‐qubit gate operation times are defined by the strength of the interaction between the qubits. In this system the two‐qubit gate operation times range from 10s to 100s of ns, which is favourable for the range of decoherence times for this system (ranging from 100s to 1000s of ns) at cryogenic temperatures, and the achievable single gate operation times, defined by the pulse lengths. The inherent limitation of pulsing at multiple resonance frequencies to achieve the necessary entangled states may be realised using circuit quantum electrodynamic (QED) architectures, as applied recently to Yb molecular spin qubits.g‐values of each spin qubit. Finally, synthetic approaches to enhance the coherence time on the Cr7Ni spin while preserving fast T1 relaxation have been reported,The key characteristics of the model multi‐qubit system, namely the weak inter‐qubit interactions and individual qubit addressability, ensuring factorised eigenstates, coupled with the disparity in II‐Cr7Ni ring RIDME interactions have been measured for the first time, and the dipolar data could be modelled to give an indication of global structural flexibility in the complex. Further, variable temperature RIDME experiments detecting on the nitroxide resonance could be selectively tuned to target either the CuII‐nitroxide or nitroxide‐Cr7Ni ring interaction, conferring individual spin centre addressability based on differing spin relaxation properties. The results presented suggest that disparity in spin relaxation dynamics can be exploited to mitigate detrimental issues of MSEs in the measurement of pairwise inter‐qubit magnetic interactions, and further, may allow us to probe the controlled decoherence of entangled qubit pairs via the fast longitudinal relaxation of an ancillary spin qubit. These results therefore aim to guide development in frequency addressable molecular multi‐qubit candidates for future quantum computation and simulation routines.To summarise, we have synthesised and measured coherent, switchable, and spectrally addressable dipolar interactions in a molecular multi‐qubit model system. Highly orientation selective CuThe authors declare no conflict of interest.As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.Supporting InformationClick here for additional data file.