Recently accumulated evidence indicates a potential association between COVID-19 and elevated susceptibility to cancer, including male genital cancer. However, the causal nature of this relationship remains unclear.In this Mendelian randomization (MR) study, we investigated the potential causal relationship between COVID-19 and male genital cancer using genetic variants as instrumental variables. We utilized summary statistics from two large-scale genome-wide association studies of COVID-19 hospitalized Vs. controls, as well as data from a population-based male genital cancer database based on European ancestry. We applied stringent quality control measures to select instrumental variables, including checking for linkage disequilibrium, removing low-quality variants, and assessing the strength of the instruments using the F-statistic. We conducted the MR  analysis using the inverse-variance weighted method and several sensitivity analyses  to test the robustness of our results.p = 0.668). The estimated causal effect was consistent across all sensitivity analyses . The leave-one-out analysis showed that there was no any sing Single-nucleotide polymorphism significantly influencing our results.Our MR analysis revealed no causal associations between COVID-19 hospitalization and the incidence of male genital cancer. In the inverse-variance weighted analysis, no causal associations were observed between patients with COVID-19 hospitalization and the incidence of male genital cancer (odds ratio = 1.000 and 95% confidence interval = 0.998-1.001, Our study provides evidence that there is no causal association between COVID-19 hospitalization and male genital cancer.  The COVID-19 pandemic is a global public health crisis that has caused unprecedented disruption to societies, economies, and healthcare systems worldwide . The panLong COVID-19 syndrome, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), is a condition in which individuals experience persistent symptoms and complications of COVID-19 long after the initial infection has resolved . SymptomCOVID-19 has been found to disproportionately affect male health compared to female health . StudiesBesides, the abovementioned registered study is an observational study . ObservaMendelian randomization (MR) is a method of analysis that uses genetic variants as instrumental variables to investigate causal relationships between exposures and outcomes. This approach leverages the random assortment of genetic variants during meiosis, which can mimic the random assignment of individuals to different exposures in a randomized controlled trial . By usinTherefore, this study was designed to investigate the causal associations between COVID-19 and cancer of the male genital tract by using a two-sample MR analysis.This MR study aims to explore the potential causal relationship between COVID-19 and male genital cancer. The study design leverages genetic variants as instrumental variables to investigate the causal association between COVID-19 hospitalization with the incidence of male genital cancer.An ethics statement may not be necessary for this MR study, as it utilizes summary statistics from previously published GWAS studies and cancer registry data. The use of publicly available data sources, in this case, does not require the approval of an ethics committee or institutional review board. However, we acknowledge the contributions of the original studies and datasets used in this analysis and follow best practices for data handling and reporting. All data were analyzed in an anonymized format to protect the privacy of study participants. The results of this study will be reported in aggregate form and will not allow for the identification of any individual participant.The study utilizes summary statistics from two large-scale genome-wide association studies (GWAS) of COVID-19 hospitalization. It is worth noting that hospitalized patients typically undergo more rigorous diagnostic procedures, which can increase the accuracy of COVID-19 diagnosis and reduce the risk of false-positive or false-negative results, as compared to individuals with mild or asymptomatic infection who may not be tested or diagnosed as thoroughly. Therefore, the inclusion of hospitalized patients in this study is expected to enhance the reliability and validity of the findings.https://gwas.mrcieu.ac.uk/datasets/ukb-d-C_MALE_GENITAL/. The detailed description of the cancer population database should be referred to the original study of cancer of the male genital, including its origin, sample size, key demographic characteristics, and the specific types of male genital cancers included. All of the selected databases are the ones with the largest sample size when we conduct this MR.The exposure variables were derived from these GWAS studies, which were conducted on samples of European ancestry, including 9,986 hospitalized COVID-19 patients and 1,877,672 controls . The outThe MR analysis was conducted using the inverse-variance weighted (IVW) method, which is a commonly used method for estimating causal effects in MR studies . We alsoIn selecting the instrumental variables (IVs) for this MR study, we applied several quality control measures to ensure the validity and strength of the instruments. Specifically, we used the following criteria to select the IVs :Genome-wide significance threshold: We selected genetic variants that were genome-wide significant (p ≤ 5 × 10^-8) in the COVID-19 hospitalization GWAS studies. This criterion ensures that the genetic variants used as IVs have a strong association with the exposure variables .Linkage disequilibrium (LD): We checked for LD between the selected genetic variants to ensure that they are not highly correlated with each other. We removed variants that were in strong LD (r^2 > 0.1 and D’ > 0.95) with other variants to avoid issues of overfitting and potential bias.Imputation quality: We excluded variants with low imputation quality scores (INFO score < 0.8) to ensure the accuracy of the genetic data used in the analysis.F-statistic: We calculated the F-statistic for each instrument to assess the strength of the instruments. We only retained instruments with an F-statistic greater than 10, indicating a strong relationship between the IVs and the exposure variables.https://gwas.mrcieu.ac.uk/phewas/ to exclude the single-nucleotide polymorphisms (SNPs) which were significantly associated with other exposures, such as age, and smoking.Potential bias: We searched Overall, the IVs selected for this study were robust and met established quality control measures to ensure the validity of the MR analysis. By using high-quality instruments, we aimed to minimize the potential for bias and increase the accuracy of the causal effect estimates between COVID-19 and male genital cancer. In the present MR analysis, R version 4.2.2 (2022-10-31) and the “TwoSampleMR” package (version 0.5.6) were used to estimate the causal associations.We identified four genetic variants associated with COVID-19 and used them as instrumental variables in our analysis . This inherent random allocation of alleles is one of the chief strengths of MR studies, offering an avenue to address confounding in observational data.Besides, in our two-sample MR analysis, the data sets for exposure  and outcome  are derived from separate cohorts. This distinction is fundamental. Given that the genetic predispositions we assess are lifelong, the temporal collection of the cancer data relative to the COVID-19 data does not influence our findings. Thus, the genetic conclusions we can draw have implications spanning an individual’s lifetime, rather than being constrained to a specific historical or present timeframe.In summary, our use of MR analysis in this study provides several advantages over traditional observational studies, including the ability to establish a causal relationship, reduce bias and measurement error, and provide insights into the underlying biological mechanisms. These advantages strengthen the validity and generalizability of our findings and highlight the importance of using this approach in future research on the relationship between COVID-19 and other cancers.While MR analysis provides several advantages over traditional observational studies, it is not without its limitations. One potential limitation of our study is the assumption of instrumental variable validity, which requires that the genetic variants used as instrumental variables are strongly associated with the exposure (COVID-19) and independent of confounding factors that may influence the outcome . While we used genetic variants with established associations in the literature and performed sensitivity analyses to assess the validity of our instrumental variables, there is always a risk of bias due to unmeasured confounding or pleiotropy . Another potential limitation of our study is the lack of generalizability to all populations. Our analysis was conducted using data from individuals of European ancestry, and it is unclear whether our findings can be extrapolated to other populations with different genetic backgrounds and environmental exposures . It is aOur MR study provides evidence that there is no causal relationship between COVID-19 susceptibility and male genital cancer. These findings have important implications for cancer screening and prevention strategies in COVID-19 care, as well as for the development of public health policies and clinical guidelines.


Background and Objective: To analyze the effects of several drug for pain prevention in adults undergoing craniotomy for elective brain surgery. Material and Methods: A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The inclusion criteria were limited to randomized controlled trials (RCTs) that evaluated the effectiveness of pharmacological treatments for preventing post-operative pain in adults (aged 18 years or older) undergoing craniotomies. The main outcome measures were represented by the mean differences in validated pain intensity scales administered at 6 h, 12 h, 24 h and 48 h post-operatively. The pooled estimates were calculated using random forest models. The risk of bias was evaluated using the RoB2 revised tool, and the certainty of evidence was assessed according to the GRADE guidelines. Results: In total, 3359 records were identified through databases and registers’ searching. After study selection, 29 studies and 2376 patients were included in the meta-analysis. The overall risk of bias was low in 78.5% of the studies included. The pooled estimates of the following drug classes were provided: NSAIDs, acetaminophen, local anesthetics and steroids for scalp infiltration and scalp block, gabapentinoids and agonists of adrenal receptors. Conclusions: High-certainty evidence suggests that NSAIDs and acetaminophen may have a moderate effect on reducing post-craniotomy pain 24 h after surgery compared to control and that ropivacaine scalp block may have a bigger impact on reducing post-craniotomy pain 6 h after surgery compared to control. Moderate-certainty evidence indicates that NSAIDs may have a more remarkable effect on reducing post-craniotomy pain 12 h after surgery compared to control. No moderate-to-high-certainty evidence indicates effective treatments for post-craniotomy pain prevention 48 h after surgery. Post-operative pain is a crucial clinical issue that has generated increased attention in recent years . DespiteCraniotomy is the most frequent cause of headache and pain for almost all types of elective cranial neurosurgical pathologies ,5. AcutePost-craniotomy pain is mainly somatic and originates from the scalp, peri-cranial muscles and soft tissues ,10,11. TThe nature of pain after craniotomy is usually pulsating or pounding . ConstanThe consequences of pain after brain surgery can be severe and long-standing, including risks of post-operative hemorrhage due to arterial hypertension, prolonged recovery time, and an increased risk of long-term headaches ,19. SeveThe aim of this meta-analysis is to analyze the effect of several drug classes to provide the best chance of reducing pain for adults undergoing craniotomy for elective brain surgery by collecting and synthesizing the results of randomized clinical trials that investigated pain-relieving drugs for this patient group, including both invasive and non-invasive routes of administration. To accurately address this research question, only studies conducted following an approved high standard were included, and a risk of bias assessment was conducted to ensure the validity of the results. Studies from various countries was analyzed to gather comprehensive and relevant information.This systematic review with meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines ,27.The inclusion criteria for this systematic review and meta-analysis were limited to randomized controlled trials (RCTs) that evaluated the effectiveness of pharmacological treatments for preventing post-operative pain in adults (aged 18 years or older) undergoing craniotomies. Non-randomized trials, observational retrospective and prospective studies, case reports and review articles were excluded to reduce the inaccuracies associated with different study designs, non-random allocation, the absence of control groups and varying inclusion and exclusion criteria. The decision to exclude the pediatric population was based on concerns regarding the accuracy of pain assessment in pediatric patients compared to that of adults, and the higher likelihood of different pain thresholds between adult and pediatric populations.This meta-analysis considered any kind of pharmacological treatment for the prevention of post-operative pain in adult patients undergoing craniotomies. The aim was to evaluate the efficacy of these treatments in reducing the incidence and intensity of post-operative pain. Non-preventive pharmacological treatments, such as patient-controlled analgesia (PCA), or non-pharmacological treatments, such as acupuncture and protocols for patient mobilization, were excluded from this meta-analysis.The main outcome measures were represented by mean differences in validated pain intensity scales, such as the Visual Analogue Scale (VAS) or the Numerical Rating Scale (NRS), being post-operatively administered at 6 h, 12 h, 24 h and 48 h. If a time point was missing, the closest available one was considered as long as it did not differ by more than 2 h. For studies reporting VAS intervals between 0 and 100, the pain intensity VAS was rescaled to an interval from 0 to 10. Studies were not included in this meta-analysis if the assessment of post-operative pain was indirectly addressed through the registration and report of analgesic drugs’ consumption, such as post-operative consumption of opioids, or through the analysis of hemodynamic parameters usually related to pain, such as arterial blood pressure or heart rate.The following databases and registers were independently screened by two reviewers (G.F. and E.P.): PubMed, CENTRAL and ClinicalTrials.gov. The initial search was concluded on 20 November 2022. We conducted an updated search on 30 December 2022. A third search stage consisted of examining any other pertinent trial being included in the reference lists of relevant articles. This third phase was jointly conducted by two reviewers.The following research terms were used to identify relevant articles: craniotomy, pain, post-operative pain, prevention, treatment and management, along with their MeSH terms. Only articles written in English were included in this investigation, and no filters were applied during the research process.Two authors (G.F. and E.P.) independently reviewed the titles and abstracts of all retrieved articles, categorizing them as included, excluded or maybe. Shortly, studies that did not meet the inclusion criteria were excluded at this stage . In the case of disagreement, the authors reached consensus through full-text review and discussion. If necessary, a third author (G.A.B.) was consulted. Next, two authors reviewed the full texts of all the initially included articles to assess their eligibility. Again, in case of disagreement, the consensus was reached by discussion or by consulting the third author. No automatic tools were employed during the articles’ selection process.Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2022) .,83.82,83Subgroup AnalysisThe patient population was constituted by both craniotomy location categories . However, subgroup analyses were not performed, as the outcome measures were not independently evaluated. Additionally, a subgroup analysis of different agents could not be conducted, as only two studies from the gabapentinoids class were identified.I2 = 0%; p = 0.14).We included two studies investigating the preventive effect of adrenal receptor agonists on post-craniotomy pain  84,85].,85.84,85Subgroup AnalysisNo subgroup analyses were conducted since all the included studies investigated the role of adrenal receptor agonists in a patient population that underwent supra-tentorial craniotomies.We included two studies investigating the combined analgesic value of adrenal receptors’ agonists and local anesthetics against local anesthetics alone for scalp block and scalp incision infiltration ,87. SenaI2 = 99%; p = 0.3) at 6 h, −2.11  at 24 h and −1.86  at 48 h.We included two studies investigating the combined analgesic value of steroids and local anesthetics against local anesthetics alone for scalp infiltration  88,89].,89.88,89Subgroup AnalysisNo subgroup analyses were conducted since all the included studies investigated the adjunctive role of steroids for scalp infiltration in a patient population of supra-tentorial craniotomies. Moreover, we were unable to conduct a subgroup analysis of the different agents since only two studies were identified.We found only one study investigating the analgesic effect of intravenously administered lidocaine for the prevention of post-craniotomy pain . The autNo sensitive analyses were conducted in this study since the pooled estimates calculated in the meta-analysis did not include studies that were judged to have a high risk of bias.The inadequate control of pain after craniotomy is a critical issue in the perioperative management of neurosurgical patients as it relates to worse surgical outcomes ,92. AgitThis meta-analysis included 29 RCTs, examining the preventive analgesic effect of NSAIDs, acetaminophen, scalp block, scalp infiltration, gabapentinoids, intravenously administered lidocaine and agonists of adrenal receptors through a direct comparison to control groups. Twelve studies (41%) were published between 2019 and 2022.The effectiveness of NSAIDs in reducing post-craniotomy pain for up to 24 h post-operatively is confirmed by the present investigation. The levels of evidence certainty (EC) were graded as moderate for the pooled estimates at 6 and 12 h and as high at 24 h. The small sample size and the indirectness caused by the employment of different anti-inflammatory agents downgraded the level of EC ,63,64. Chigh EC that acetaminophen has a sensible effect on reducing post-operative pain 24 h after surgery. This result was supported by a low degree of heterogeneity and an adequate sample size in the included studies.This meta-analysis failed to confirm the efficacy of acetaminophen in reducing post-craniotomy pain at 6 and 12 h after surgery with a moderate-to-low degree of EC. This result took into account a relatively low number of included patients and a moderate-to-high level of heterogeneity. Differently, there was moderate degree of EC. The scalp block technique failed to be identified as effective for pain prevention at 12, 24, and 48 h after surgery. Nevertheless, this result has a very low degree of EC in consideration of the high level of inconsistency, indirectness and imprecision of the included studies and the high risk of reporting bias for the studies included in the pooled analysis at 24 h.The efficacy of scalp block for post-craniotomy pain 6 h after surgery is suggested by the current investigation. This result is supported by a high degree of EC. The same result failed to be confirmed at 24 h despite it having a very low EC level.Subgroup analyses revealed a significant effect of ropivacaine in reducing post-craniotomy pain at 6 h after surgery with a low degree of EC since they were burdened by a serious level of imprecision related to the small sample size.The present meta-analysis could not support the impact of scalp infiltration on reducing pain at 6, 12 and 24 h after craniotomy. Nevertheless, these results showed a low degree of EC secondary to a remarkable level of indirectness due to the employment of different drugs  and some degrees of imprecision caused by a small sample size.The pooled estimates revealed gabapentinoids to be effective for post-craniotomy pain 24 h after surgery. Conversely, their efficacy failed to be confirmed at 48 h. However, these results must be considered with care because of a low to very low due to significant unexplained heterogeneity, a limited cohort of patients and a high level of indirectness caused by different drugs. Finally, no pooled estimates could be calculated to measure the analgesic value of the intravenously administered lidocaine compared to that of the control group, and the one of adrenal receptors’ agonists combined with local anesthetics compared to local anesthetics alone for scalp block and scalp incision infiltration.The current meta-analysis failed to identify any positive effects of agonists of adrenal receptors on improving post-craniotomy pain compared to that of the control group. Likewise, no differences in post-craniotomy pain were demonstrated when the combination of steroids and local anesthetics were compared to local anesthetics alone. The level of EC was revealed to be A “Summary of Findings” Table generated by GRADEpro GDT software is available as The present meta-analysis provides high-certainty evidence that NSAIDs and acetaminophen may have a more moderate effect on reducing post-craniotomy pain 24 h after surgery compared to that of the control groups. Further, there is high-certainty evidence suggesting ropivacaine scalp block may have a larger effect on reducing post-craniotomy pain 6 h after surgery compared to that of the control groups. Moderate-certainty evidence indicates NSAIDs may have a more noticeable effect on reducing post-craniotomy pain 12 h after surgery compared to that of the control group. No moderate-to-high-certainty evidence indicates effective treatments for post-craniotomy pain prevention 48 h after surgery.


The renin–angiotensin system (RAS) is critically involved in their pathophysiology and is counter-balanced by both angiotensin-converting enzyme 2 (ACE2), the functional receptor of SARS-CoV-2, and the kallikrein–kinin system (KKS). Considerable research interest with respect to COVID-19 treatment is currently being directed towards the components of these systems. In earlier studies, we noticed significantly reduced carboxypeptidase N  activity and excessive angiotensin-converting enzyme  activity in the sera of both hospitalized COVID-19 patients and a subgroup of convalescent patients. The data had been obtained using labeled bradykinin (BK) as a reporter peptide, which is a target of both CPN and ACE. The data were supplemented with mass-spectrometry-based serum proteomic analysis. Here, we hypothesize that the degree of BK serum degradation could be indicative of Long COVID. (2) Review and Discussion: The recent literature is briefly reviewed. The fact that the levels of the BK serum degradation products did not reach normal concentrations in almost half of the patients during convalescences could have been partially due to a dysregulated RAS. (3) Conclusions: Standard tests for routine patient care in Long COVID come often back normal. We suggest that the measurement of selected members of the RAS such as ACE and angiotensin II or the use of our BK degradation assay could identify Long COVID candidates. Clinical studies are required to test this hypothesis. It was recognized early on during the corona virus infectious disease 2019 (COVID-19) pandemic that comorbidities such as hypertension and cardiovascular disease present major risk factors for severe illness and fatal outcomes. Two facts caused the spotlight in COVID-19 research on the renin–angiotensin system (RAS): (1) It is critical to retain blood pressure homeostasis, and according to experimental and clinical data, severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection promotes a rise in blood pressure during the acute phase of infection . In earlier work, we have studied RAS components in sera of hospitalized COVID-19 and convalescent patients with both a bradykinin (BK) degradation assay  and highMass spectrometric expression analysis of undepleted patient sera revealed significantly different protein profiles of hospitalized and convalescent patients as well as healthy probands as expected, but it also showed six distinct subgroups for the first cohort . The proRemarkably, the serum concentration of the precursor protein in the RAS, angiotensinogen, correlated with disease severity in hospitalized patients indicating that angiotensin (Ang) II-stimulated signaling was dysregulated. A clear distinction based on co-morbidities was not observed for the subgroups of hospitalized patients. In fact, hypertensive and antihypertensiva-taking patients were found in all groups. Interestingly, we observed that none of the hospitalized patients taking ACE inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) died in contrast to half of the untreated hypertensive patients . Indeed,Below, we briefly summarize the current knowledge about the RAS in the light of our own findings. We discuss the data from our study in the context of recent information regarding the so-called Long COVID syndrome  and demoThe main product of the classical RAS is Ang II, which is formed from angiotensinogen with the assistance of renin and ACE. The binding of Ang II to its receptors leads to effects such as elevated blood pressure and disturbed renal water sodium balance. The counter-regulatory arm of the RAS involves ACE2, which cleaves Ang II and generates the products Ang 1–9), Ang 1–7) and alamandine, with opposite effects to those of Ang II. ACE2 also serves as a virus entry receptor during SARS-CoV-2 infection, leading to dysregulation. Another counter-balance to the RAS is the KKS, in which BK production contributes to blood-pressure-decreasing effects  and alam. BK is i, Ang 1–7Considering these main processes involving the inverse relationship between ACE and ACE2, the use of ACEIs/ARBs has been proposed to counteract the inflammatory effects of COVID-19 infection by shifting metabolic activity away from the AT1 receptor pathway toward the AT2/Mas receptor pathways, but these inhibitors may potentially also increase ACE2 activity . The corMany papers suggest that an imbalanced RAS may be associated with severe COVID-19 progression  with an immense impact on both personal wellbeing and the healthcare system . ThroughThe post-acute sequelae of the infection are persistent, exacerbated or newly incident and thus difficult to diagnose and treat. Standard tests in routine patient care often come back normal, and it takes symptom-specific testing, of which, many providers are not aware . As a reIn our earlier study ,6, we deReduced BK serum degradation can result from both impaired serum CPN and dysregulated ACE activity ,38. In oUsing BK degradation for measuring the protease (CPN and ACE) activity in patients’ sera, we noted a general reduction in the BK degradation capacity in hospitalized COVID-19 patients, but also in some convalescent patients. CPN activity was decreased and contributed to a large extent to the overall reduced serum BK degradation capacity. Increased values for the BK fragment DBK1–5, which is generated by ACE, were, however, also detected. These observations in some convalescent patients raised the question of whether the assay results could be indicative of Long COVID, in particular, because the DBK1–5 level significantly correlated with COVID-19 severity in hospitalized patients. This question can only be answered by dedicated clinical studies. They have potential, because the BK assay is a low-cost/low-tech procedure based on thin-layer chromatography  that canWhen designing the clinical studies, it is important to skillfully assemble patient cohorts with regard to co-morbidities. Diseases like metabolic syndrome, in particular hypertension, directly involve the RAS, and they are known risk factors in this virus infection. Care must be taken to have sufficiently large cohorts of untreated, ACEI- and ARB- (or otherwise-) treated hypertensive patients to be able to draw significant conclusions, because the medication influences the assay results. In fact, we have learned from the serum proteomics experiments that multiple parameters other than those typically considered during the assembly of patient cohorts  may influence the results. We detected six distinct groups among the hospitalized patients, which were distinguished by their serum protein profiles. These groups seemed to represent subsets of different pathophysiologies . A correlation with co-morbidities such as hypertension or diabetes could, however, not be detected. In fact, hypertensive patients were present in all groups. Clearly, such subgroups should not be combined in subsequent data mining. The results would only show the most striking differences among the major groups of probands, and subtle differences would go unnoticed. These observations may be one reason for the bias seen in COVID-19 research , and theIn summary, we have revisited earlier proteomics data and results on serum protease activity obtained with BK as a reporter peptide from hospitalized and convalescent COVID-19 patients ,6. We foThis paper discusses data generated in two earlier studies ,6 of 45


To estimate vaccine effectiveness for preventing covid-19 related hospital admission in individuals first infected with the SARS-CoV-2 virus during pregnancy compared with those of reproductive age who were not pregnant when first infected with the virus.Population based cohort study.Office for National Statistics Public Health Data Asset linked dataset, providing national linked census and administrative data in England, 8 December 2020 to 31 August 2021.815 477 females aged 18-45 years (mean age 30.4 years) who had documented evidence of a first SARS-CoV-2 infection in the NHS Test and Trace or Hospital Episode Statistics data.Hospital admission where covid-19 was recorded as the primary diagnosis. Cox proportional hazards models, adjusted for calendar time of infection, sociodemographic factors, and pre-existing health conditions related to uptake of the covid-19 vaccine and risk of severe covid-19 outcomes, were used to estimate vaccine effectiveness as the complement of the hazard ratio for hospital admission for covid-19.Compared with pregnant individuals who were not vaccinated, the adjusted rate of hospital admission for covid-19 was 77%  lower for pregnant individuals who had received one dose and 83% (76% to 89%) lower for those who had received two doses of vaccine. These estimates were similar to those found in the non-pregnant group: 79% (77% to 81%) for one dose and 83% (82% to 85%) for two doses of vaccine. Among those who were vaccinated >90 days before infection, having two doses of vaccine was associated with a greater reduction in risk than one dose.Covid-19 vaccination was associated with reduced rates of hospital admission in pregnant individuals infected with the SARS-CoV-2 virus, and the reduction in risk was similar to that in non-pregnant individuals. Waning of vaccine effectiveness occurred more quickly after one than after two doses of vaccine. Pregnancy is a risk factor for severe illness and death after infection with the SARS-CoV-2 virusEvidence suggests that covid-19 vaccines are effective for preventing severe outcomes in pregnant individualsResearch directly comparing vaccine effectiveness between pregnant and non-pregnant individuals of reproductive age at the population level are lackingThis study provides real world evidence that covid-19 vaccination reduced the risk of hospital admission by a similar amount in both individuals infected with the SARS-CoV-2 virus during pregnancy and in those who were not pregnant when infected, during the alpha and delta variant dominant periods of the covid-19 pandemic in EnglandThis study adds to the body of evidence demonstrating effectiveness of covid-19 vaccination for reducing the risk of severe illness among those infected with SARS-CoV-2 during pregnancyFurther research is needed to understand waning effectiveness of covid-19 booster vaccines in pregnancyPhysiological changes that take place during pregnancy  increase the risk of experiencing severe outcomes of covid-19.Covid-19 vaccines have been shown to be highly effective at reducing the risk of hospital admission and death related to covid-19 in clinical trials and real world observational studies.An observational cohort study reported that two doses of the Pfizer-BioNTech (BNT162b2) mRNA vaccine was 89% effective in preventing covid-19 related hospital admissions in pregnant individuals during the periods when the wild-type and alpha variants of the SARS-CoV-2 virus were predominant in Israel, which was similar to the estimated efficacy in the general population.We conducted a population based cohort study with data from the Office for National Statistics Public Health Data Asset. The Office for National Statistics Public Health Data Asset is a linked dataset combining data from the 2011 census of England, mortality records, the General Practice Extraction Service Data for Pandemic Planning and Research (GDPPR), Hospital Episode Statistics, vaccination data from the National Immunisation Management System, and data from the NHS Test and Trace pillar 1  and pillar 2 .To obtain NHS numbers, data from the 2011 census were linked to the 2011-13 NHS patient registers with deterministic and probabilistic matching, with an overall linkage rate of 94.6%  was estimated as 99.4% ; 1.6% of these links involved multiple 2021 census records linked to the same NHS number, which were excluded after deduplication. The 2021 census was then linked to the Public Health Data Asset with NHS numbers.The study cohort comprised females who had a first recorded SARS-CoV-2 infection between 8 December 2020 (the start of the vaccination campaign in the UK) and 31 August 2021 (with no evidence of a previous infection) and were listed in the 2011 census and living in a private household; aged 18-45 years at the start of the study period; linked to the 2011-13 NHS patient registers; linked to at least one GDPPR record; and resident in England according to the most recent postcodes held in GDPPR. Data for sex were taken from self-reported responses to the following question at the 2011 census: "What is your sex?"; response options were "male" or "female."The index date for the start of follow-up was the earliest evidence of SARS-CoV-2 infection within the study period. Evidence of SARS-CoV-2 infection was determined by a positive swab test result for the SARS-CoV-2 virus with a polymerase chain reaction (PCR) test or a lateral flow device recorded in the NHS Test and Trace data, or a hospital admission or outpatient appointment with an ICD-10  code of U07.1  or U07.2  as the primary or secondary diagnosis.Two data sources were used to identify pregnancy status at the time of SARS-CoV-2 infection. NHS birth notifications data identified those who were pregnant when infected with the SARS-CoV-2 virus and had a live birth or stillbirth. Hospital Episode Statistics data identified individuals who were pregnant when they were infected with the SARS-CoV-2 virus but for whom a birth notification was not recorded . 10.1136/bmjmed-2022-000403.supp1Supplementary dataVaccination status was derived from data from the National Immunisation Management System and was defined as the number of doses received at least 14 days before the index date. Participants were classified as single or double vaccinated if they had received one or two doses, respectively, of a covid-19 vaccine at least 14 days before infection.We adjusted for sociodemographic factors known from previous studies to be associated with the risk of severe covid-19 outcomes, and vaccine uptake  by vaccination status and pregnancy status, standardised to the 2013 European Standard Population.v >90 daysTo assess differential waning of vaccine effectiveness between the single and double vaccinated individuals, we grouped the analysis by time since last vaccine dose ; 33 549 (4.1%) were identified as pregnant when they were infected with the SARS-CoV-2 virus .Among those identified as pregnant at the time of SARS-CoV-2 infection, 87.2% had not received a vaccine, 8.1% were single vaccinated, and 4.7% were double vaccinated. Among non-pregnant individuals, 68.6% had not received a vaccine, 16.4% were single vaccinated, and 15.0% were double vaccinated.Overall, 9889 hospital admissions for covid-19 occurred in the study period: 1895 (19.2%) were among pregnant individuals , and 180For both pregnant and non-pregnant individuals, age standardised rates of covid-19 related hospital admission (per 100 000 infections) were higher among those who had not received a vaccine compared with those who were single or double vaccinated . Among pCompared with the non-vaccinated pregnant group, vaccine effectiveness for preventing covid-19 related hospital admission was 77%  for the single vaccinated pregnant group and 83% (76% to 89%) for the double vaccinated pregnant group . CorrespAnalysis of Schoenfeld residuals plots indicated potential non-proportional hazards for vaccination after about four weeks of follow-up . We therIn the pregnant and non-pregnant groups, vaccine effectiveness was similar in those single or double vaccinated 14-90 days before the first infection . Among tOur study showed that vaccination against covid-19 was associated with a reduced risk of covid-19 related hospital admission during the periods when the alpha and delta variants of the SARS-CoV-2 virus were predominant in England, in individuals of reproductive age, regardless of their pregnancy status when infected with the virus. The effectiveness of the covid-19 vaccines against hospital admission waned more quickly after one than after two doses of vaccine in both pregnant and non-pregnant individuals.Our findings are consistent with other studies showing that covid-19 vaccination is effective in reducing the risk of severe illness after infection with the SARS-CoV-2 virus in pregnancy.We also found that having two doses of a covid-19 vaccine was associated with greater protection against hospital admission for covid-19 than one dose among those vaccinated >90 days before infection, suggesting faster waning of vaccine effectiveness after one dose of vaccine. The recommended interval between first and second doses of vaccine is 84 days. Participants who were single vaccinated >90 days before infection might have had to delay their second vaccination because they were infected with the SARS-CoV-2 virus . Alternatively, participants might have decided to delay their second dose of the vaccine if they had an adverse reaction to the first dose or because of concerns about the safety of the vaccine if they discovered they were pregnant after their first dose. Because data from the National Immunisation Management System cover England only, some participants could have received their second dose of vaccine outside of England and been misclassified as single vaccinated when they were infected. This number is likely to be small, however; 94.9% of participants who were single vaccinated when they were infected had a second dose recorded in the National Immunisation Management System data at a later date.Our study did not assess effectiveness against the omicron variant of the virus or the effectiveness of booster vaccines. Previous evidence suggests that three doses of vaccine are more effective than two, however, for preventing severe illness in pregnancy after infection during the omicron variant period.The main strength of our study was that we used the nationwide linked data asset combining the 2011 and 2021 censuses of England, mortality records, hospital records, birth notifications data, vaccinations data, and SARS-CoV-2 testing data from national testing programmes. Based on hospital data and data from birth notifications, we identified individuals who were pregnant when they were infected with the SARS-CoV-2 virus. We adjusted for a range of sociodemographic characteristics and pre-existing health conditions associated with uptake of the vaccine and the risk of severe covid-19 outcomes. For most participants, sociodemographic variables were based on up-to-date data from the 2021 census.A limitation of our study was that the study population might not fully represent the at risk population. The cohort did not include people living in England in 2011 who did not participate in the 2011 census  suggested that about 40% of people who test positive for the SARS-CoV-2 virus do not develop symptoms within 35 days.Although the precise real world sensitivity and specificity of reverse transcription PCR tests and rapid antigen tests for SARS-CoV-2 are not known, studies suggest that the false positive rate is generally low.Hospital admissions for covid-19 were defined as inpatient admissions, where covid-19 was recorded as the primary diagnosis. These admissions will include some hospital admissions where the initial reason for admission was not related to covid-19, but the patient was subsequently diagnosed as having, and then treated for, covid-19 while in hospital. Hospital admissions for covid-19 will also include hospital acquired infections, which are probably more common among pregnant individuals who are more likely to have contact with hospitals than those in the general population.Pregnant individuals were identified as a vulnerable group and prioritised for covid-19 vaccination in December 2021 by the Joint Committee on Vaccination and Immunisation in the UK. The Royal College of Obstetricians and Gynaecologists strongly recommend that covid-19 vaccines are offered to all pregnant individuals.During the periods when the alpha and delta variants of the SARS-CoV-2 were predominant in England, covid-19 vaccination was associated with a reduced risk of covid-19 related hospital admission in individuals infected with SARS-CoV-2 during pregnancy as well as among non-pregnant individuals. Increasing vaccine uptake during pregnancy might contribute to reduced levels of avoidable harms to pregnant individuals associated with covid-19. These data add to the evidence base about the protective effect of vaccination for those infected with SARS-CoV-2 during pregnancy by providing real world evidence in a population that was originally excluded from the vaccine trials.


We aimed to develop a risk score to calculate a person’s individual risk for a severe COVID-19 course (POINTED score) to support prioritization of especially vulnerable patients for a (booster) vaccination.This cohort study was based on German claims data and included 623,363 individuals with a COVID-19 diagnosis in 2020. The outcome was COVID-19 related treatment in an intensive care unit, mechanical ventilation, or death after a COVID-19 infection. Data were split into a training and a test sample. Poisson regression models with robust standard errors including 35 predefined risk factors were calculated. Coefficients were rescaled with a min–max normalization to derive numeric score values between 0 and 20 for each risk factor. The scores’ discriminatory ability was evaluated by calculating the area under the curve (AUC).Besides age, down syndrome and hematologic cancer with therapy, immunosuppressive therapy, and other neurological conditions were the risk factors with the highest risk for a severe COVID-19 course. The AUC of the POINTED score was 0.889, indicating very good predictive validity.The POINTED score is a valid tool to calculate a person’s risk for a severe COVID-19 course.The online version contains supplementary material available at 10.1007/s10389-023-01884-7. German Standing Committee on vaccination [(STIKO [Ständige Impfkommission]) recommended a second booster vaccination for (i) people 70 years and older, (ii) residents and personnel of long-term care facilities, (iii) people with an immunodeficiency from the age of five, and (iv) employees of medical facilities, especially those with direct patient contact  in Germany. Data from two German Local Health Care Funds [AOK PLUS Sachsen and AOK Bayern], the BARMER, and the DAK-Gesundheit and the Techniker Krankenkasse (TK) as well as the research database of the Institute of Applied Health Research Berlin including anonymized claims data of company health insurances [Betriebskrankenkasse (BKK)] were used for the purposes of this analysis. Claims data from the AOK PLUS Sachsen and from DAK-Gesundheit were analyzed at the Center for Evidence-Based Healthcare (ZEGV) at the TU Dresden and Vandage GmbH, respectively. In total, the data included information of approximately 38 million persons, which corresponds to approximately 46% of the German population.In addition to sociodemographic information (age and sex) and vital status , German claims data contain information about performed ambulatory services , diagnoses documented in the ambulatory and hospital setting  and procedures conducted  as well as drug prescription data  Classification). Longitudinally linked data from the years 2019 and 2020 have been used for the purposes of this study. Due to German data protection law, pooling of individual-level data was not feasible. Hence, six harmonized health insurance data sets were analyzed separately by authorized institutes or the healthcare research department within the respective health insurance.Adult patients with a confirmed ambulatory and hospital COVID-19 diagnosis  between 27 January 2020 and 31 December 2020 were included in the analysis. COVID-19 patients had to be continuously enrolled in the SHI in the year 2019 up to the date of the COVID-19 infection and from their COVID-19 infection until death or 31 December 2020, whichever came first. Based on COVID-19 related ambulatory and hospital services the beginning of the COVID-19 infection was determined. Claims data from the year 2019 were used to assess risk factors for a severe course of COVID-19.The outcome severe COVID-19 course was defined as COVID-19 related treatment in an intensive care unit, mechanical ventilation, or death after a COVID-19 infection. Intensive care treatment and mechanical ventilation had to occur within a hospitalization for which COVID-19 was documented as a discharge diagnosis. Deaths occurring within 30 days after a COVID-19 infection, during a COVID-19 related hospitalization, or within 14 days following such hospitalizations were defined as COVID-19 related. An overview of the procedure codes used to identify intensive care treatment and mechanical ventilation is provided in the supplementary material Based on an umbrella review by Treskova-Schwarzbach et al. (20) and further the recommendations of the STIKO, we defined 35 conditions that were associated with a severe course of COVID-19. The conditions were defined using ICD-10 codes derived from hospital discharges and ambulatory physicians and psychotherapists in the year prior to the COVID-19 infection. Ambulatory diagnoses had to be documented in at least two quarters in 2019. Furthermore, prescriptions for specific therapies were required to validate ambulatory diagnoses of asthma, coronary heart disease, COPD, depression, diabetes, hematologic, metastatic, and solid cancer with therapy, heart failure, hypertension, and severe psychiatric diseases. The definition of risk factors is available from the corresponding author upon request.Statistics for the entire COVID-19 cohort across all data sites were summarized descriptively. To develop the score, the total cohorts of COVID-19 patients in 2020 selected at each data site were split into training and a test data set. The training data sets, used to develop the score, included a random 90% sample of the total study population at the respective data site. The random test data set included the other 10% of the study population and was used to assess the performance of the developed score.To evaluate whether effect modification of certain risk factors by age was present, age stratified Poisson regression models with robust standard errors using the training data sets were estimated Zou . To estiThe models with the selected interaction terms were fitted at each data site and pooled again using meta-analysis. These final coefficients were rescaled with a min–max normalization on the scale 0 to 20  of the receiver operating characteristics (ROC) and the Youden index, the point of the ROC curve with the highest combined true positive rate (TPR) and false positive rate (FPR). The performance of the pooled score model was evaluated separately at each site. Aggregated statistics about the grouped age and score distribution and prediction performance (area under the curve) were pooled at ZEGV. The performance of the grouped risk score model was compared to the performance of a score model based on grouped age only.A total of 623,363 patients with a confirmed COVID-19 infection between 27 January 2020 and 31 December 2020 were included in the analysis at all participating data sites. Approximately 42% were male and 22% were above the age of 64. Table The min–max normalized POINTED score values as well as the risk ratios derived from the pooled Poisson regression results are displayed in Table Factors that increase the risk of a severe COVID-19 disease course were more prevalent in the higher age groups  or a score based on age alone (0.870)  for the age score and 20 points and more  for the POINTED risk score including sex and comorbidities as risk factors. Given that a vaccination would prevent 100% of severe courses of COVID-19 in people 65 years and older in the test data , 2707 cases of severe COVID-19 cases could have been prevented  for a severe COVID-19 disease course in a population of 623,363 COVID-19 patients in Germany which aimed to optimize prioritization for a COVID-19 vaccination by considering the potentially cumulative effect of different comorbidities. The score adequately predicted a severe course of COVID-19 (AUC 0.889) in a validation cohort of 62,336 German COVID-19 patients. Using the presented methodology individuals can be prioritized for vaccination in descending order of the estimated risk score per person. The additive score allows for the consideration of multiple risk factors since individuals with multiple low risk conditions might have an equal risk for a severe COVID-19 course as patients with one major risk factor only. The POINTED score performed only slightly better than a model based on age only in prediction of a severe course of COVID-19. This underlines that a risk stratification by age alone is also a feasible way for prioritization. However, younger patients with major chronic diseases benefit from the POINTED risk score as they would qualify for an earlier vaccination than when only age is used for prioritization. On the other hand, older patients with an age below 80 and no or only minor documented chronic diseases would eventually have to wait longer. Furthermore, the score can be used for prioritization within age groups.Jucknewitz et al. also identified and quantified risk factors for a severe course of COVID-19  to calculate a person’s individual risk for a severe course of COVID-19. This supports the prioritization of especially vulnerable patients for booster vaccinations or other protective public health measures to prevent severe courses of disease.ESM 1(DOC 23 kb)


To support an update of World Health Organization (WHO)'s Living Clinical management guidelines for COVID-19  5-day isolation, with no test to release; (2) removal of isolation based on a negative test; and (3) 10-day isolation, with no test to release. The model incorporates estimates of test positivity rates, effective reproduction number, isolation adherence, false negative rate, and hospitalisation rates or case fatality rates. To assess the impact of varying isolation adherence and false negative rates on rapid antigen testing, we conducted some sensitivity analyses. We used the Grading of Recommendations Assessment, Development and Evaluation approach to assess certainty of evidence. The protocol is registered with PROSPERO (CRD42022348626).Fifteen studies addressing persistent test positivity rates including 4188 patients proved eligible. Asymptomatic patients  had a significantly lower rapid antigen test positive rate than symptomatic patients  on day 5. The rapid antigen test positive rate was 21.5%  on day 10. Our modelling study suggested that the risk difference (RD) for asymptomatic patients between 5-day isolation and 10-day isolation in hospitalisations  14 more to 33 more) and mortality  of secondary cases proved very small (very low certainty). For symptomatic patients, the potential impact of 5- versus 10-day isolation was much greater in hospitalisations  and mortality . There may be little or no difference between removing isolation based on a negative antigen test and 10-day isolation in the onward transmission leading to hospitalisation or death, but the average isolation period (mean difference −3 days) will be shorter for the removal of isolation based on a negative antigen test (moderate certainty).5 days versus 10 days of isolation in asymptomatic patients may result in a small amount of onward transmission and negligible hospitalisation and mortality; however, in symptomatic patients, the level of onward transmission is concerning and may lead to high hospitalisation and death rates. The evidence is, however, very uncertain.10.13039/100004423WHO. Isolating patients with confirmed COVID-19 and quarantining individuals with a high risk of recent infection remain widely used strategies to prevent the spread of SARS-CoV-2. There are no prior systematic reviews to evaluate effects relevant to decisions regarding protocols for ending COVID-19 isolation. Many modelling studies have, however, evaluated the impact of 5 days of isolation or alternative strategies (e.g. 7 days and 10 days) with or without one negative lateral flow device on secondary infections or additional transmission risk. However, none has focused on the most patient-important outcomes of onward transmission leading to hospitalisation or death. The optimal isolation duration for patients with COVID-19 remains unclear. To address this knowledge gap, we aimed to conduct random-effects meta-analyses, using the WHO COVID-19 database, to summarise testing rates of persistent test positivity rates after COVID-19 infection and use a model to compare the effects of the 5-day isolation and removal of isolation based on a negative antigen test with 10-day isolation on onward transmission leading to hospitalisation and death.To our knowledge, this is the first systematic review and modelling study to provide estimates of the most patient-important outcomes of onward transmission leading to hospitalisation or death for the 5-day isolation and removal of isolation based on a negative antigen test versus 10-day isolation. This study demonstrates that for symptomatic patients the 5-day isolation may increase onward transmission and thus hospitalisation and mortality of secondary cases compared with the 10-day isolation. For asymptomatic patients, the increase in hospitalisations and death was small. Removal of isolation based on a negative antigen test will probably shorten the average isolation period compared with isolating all patients for 10 days.Our study provides evidence that 5-day isolation, compared to 10-day isolation, may result in a small amount of onward transmission and subsequent hospitalisation and mortality in asymptomatic patients; in contrast, in symptomatic patients, the level of onward transmission is concerning and may lead to high hospitalisation and death rates.,Coronavirus disease 2019 (COVID-19) has, as of March 26, 2023, resulted in over 761 million confirmed cases and more than 6.8 million deaths worldwide.,The World Health Organization (WHO) recommendations, published on June 17 2020Since the COVID-19 outbreak, SARS-CoV-2 variants have changed from the initial outbreak strain to the delta variant and, most recently, the omicron variant. Compared to previous SARS-CoV-2 variants, the omicron variant is both more transmissible and has a shorter incubation period but has lower viral loads at diagnosis and a generally less severe course.There are no prior systematic reviews to evaluate effects relevant to decisions regarding protocols for ending COVID-19 isolation. Many modelling studies have, however, evaluated impact of 5 days of isolation or alternative strategies (e.g. 7 days and 10 days) with or without one negative lateral flow device on secondary infections or additional transmission risk.To support an update of WHO Living Clinical management guidelines for COVID-19,This rapid systematic review adhered to the Cochrane guidance for rapid reviewsWe conducted this review following the WHO predefined population, intervention, comparator, and outcome criteria: randomised controlled trials or observational studies that directly compared the impact of 5-day isolation and removal of isolation based on a negative antigen test with the current WHO-recommended isolation period of 10 days for patients with COVID-19 on onward transmission leading to hospitalisation or death. Because we found no direct evidence addressing the question in either randomised trials or observational studies, we included evidence regarding SARS-CoV-2 testing positivity  from 5 days after documented infection onward. On the basis of this evidence, and the best evidence regarding a model to estimate onward transmission leading to hospitalisation or death.We included clinical studies of any design with patients with COVID-19 confirmed by PCR test or rapid antigen test addressing the impact of any isolation strategy on preventing the spread of COVID-19. There were no restrictions on publication language, publication status , age of patients, the severity of COVID-19, variants of SARS-COV-2, comorbidity of patients, isolation location, or co-interventions. We excluded studies enrolling people with suspected or probable COVID-19 (over 20% of participants) or contacts with confirmed COVID-19.The patient-important outcomes of interest were onward transmission leading to hospitalisation or death. Viral culture positivity, rapid antigen test positivity, and PCR test positivity provided indirect evidence.With the aid of an expert librarian from the WHO, we searched the WHO COVID-19 database up to February 27, 2023. The WHO COVID-19 database is a comprehensive multilingual source of current literature on the topic, including global literature from over 25 bibliographic and grey literature sources. https://covidence.org/) for screening. Two reviewers independently screened titles and abstracts and subsequently the full texts of potentially eligible records. Reviewers resolved disagreements by discussion or, if necessary, by consultation with a third reviewer.We used Covidence ; patient characteristics ; characteristics of isolation ; and data on each outcome of interest.To assess the risk of bias in eligible studies regarding test positivity after infection, we used five domains of the Quality In Prognosis Studies (QUIPS) tool2 statistic. When 10 or more studies were available for an outcome, we planned to assess publication bias using Egger's test.The protocol included plans to pool hospitalisation and mortality data (PROSPERO: CRD42022348626) but such direct evidence proved unavailable. Eligible studies reported the SARS-CoV-2 virus testing positivity rates following diagnosis. We performed meta-analyses for rapid antigen test, viral culture, and PCR test data, separately. Using R  we performed meta-analyses to estimate proportions and associated 95% confidence intervals (CIs) using the restricted maximum likelihood (REML) method with the random-effects model.To estimate the impact of different isolation strategies on patient import outcomes , we first performed a modelling study (multiplication equations) and further conducted a more complex microsimulation modelling study as a sensitivity analysis. We modelled the impact of three different isolation strategies for COVID-19: 5-day isolation ; removal of isolation based on negative antigen test ; 10-day isolation . We compared the impact of the 5-day isolation and the removal of isolation based on a negative antigen test with 10-day isolation on onward transmission leading to hospitalisation and death.,,We modelled a sample of 10,000 individuals with confirmed COVID-19. To estimate the hospitalisation and death for secondary cases of 5-day isolation and 10-day isolation, we used an effective secondary reproduction number of 0.96 (95% CI 0.72 to 1.2),Given the assumption that patients with a negative rapid antigen test are non-infectious, onward transmission, hospitalisation, and death using strategies of terminating isolation at the first negative antigen test will be identical to the 10-day isolation strategy. To calculate the average isolation period associated with the strategy of isolation terminated with the first negative test, we used the following equation:As a sensitivity analysis, we further performed a more complex microsimulation modelling study using the model developed by Quilty and colleagues,As requested by the WHO guideline panel, we performed pre-specified subgroup analyses by symptom status (asymptomatic versus symptomatic patients with a prior subgroup hypothesis that asymptomatic patients would have a lower positive rate). We performed meta-regression analyses for the proportion of fully vaccinated patients (hypothesising a lower positive rate in studies with a higher proportion of fully vaccinated patients). If at least two studies provided information on a subgroup, we performed within-study subgroup analyses. To assess the credibility of significant subgroup effects, we used a version of the Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN) tool, originally developed for randomised trials and meta-analysis of randomised trials, modified for the issue of test positivity over the post-infection period.For results of meta-analyses of SARS-CoV-2 testing positivity rates following diagnosis, we used the GRADE  approach for overall prognosis in broad populationsNot applicable.The funder had no role in study design, data collection, analysis, and interpretation, or writing of the manuscript and the decision to submit.The electronic database search identified 3988 records. After screening 3611 titles and abstracts and 52 full texts, 15 studies,,,,,,,Eleven studies42,,,,,,,,,,Moderate certainty evidence showed the pooled percentage of patients with positive rapid antigen test was 52.3%  23 more hospitalisations of secondary cases per 10,000 patients isolated, 95% UI 14 more to 33 more) and 90-day mortality . For symptomatic patients, the 5-day isolation may increase hospitalisation  and mortality  compared with the 10-day isolation . AppendiThere may be little or no difference in the hospitalisation and mortality for secondary cases between removing isolation based on a negative antigen test before 10 days and at the 10-day isolation (very low certainty), but the average isolation period (mean difference −3 days) will probably be shorter for the removal of isolation based on a negative antigen test compared with 10-day isolation  that chance could not easily explain and that met ICEMAN criteria for a moderate credibility subgroup analysis. The percentage of positive cases decreased over the isolation time reaching, for the entire group, 21.5% on day 10.Our primary modelling study yields very low certainty of evidence on onward transmission leading to hospitalisation or death. It does suggest, however, that for symptomatic patients the 5-day isolation may increase onward transmission and thus hospitalisation and mortality of secondary cases compared with the 10-day isolation by a magnitude most would consider important . For asyOur review is limited in that no studies, either randomised or observational, have directly addressed the impact of variable durations of isolation on forward transmission and its important possible consequences on hospitalisation and mortality. We therefore had to address the issue with indirect evidence that informed our modelling study. This modelling study has substantial uncertainties with respect to several parameters including effective reproduction number, hospitalisation rate, and case fatality rate. Some reassurance regarding the credibility of the results comes, however, from similar results in an alternative modelling approach.In contrast to previous attempts to model the possible consequences of isolation periods, we conducted a systematic review of one key aspect of the relevant indirect evidence: the SARS-CoV-2 virus test positivity from 5 to 14 days after diagnosis. The strengths of this review include a comprehensive search, duplicate assessment of eligibility, independent checking of data abstraction, and appropriate statistical analysis, including the approach to addressing a key subgroup hypothesis: results confirmed the hypothesised markedly greater test positivity rates at 5 days in those with or without symptoms.Twenty-seven percent of studies in our review were preprints that have yet to undergo peer-review process, and therefore their results may differ from the final published version. However, the likelihood of results changing is low.To provide evidence of patient-important outcomes, we further performed modelling studies relying on the results of our review of test positivity studies. Strengths of our model include its transparency. To reflect the currently dominant variant of concern, for input parameters, we used data specific to the Omicron variant when available. Finally, our relatively simple model provided results similar to applying our parameter estimates to a more complex microsimulation model.The main limitation of the model is uncertainty around key parameters, in particular reproduction number and hospitalisation rate. These include some parameters  in which data specific to the Omicron variant were not available, requiring use of data from the overall SARS-COV-2 variants. Owing to limited data, we were unable to estimate outcomes for some subgroups of patients . These limitations led us to classify the evidence regarding hospitalisation and death as very low certainty. The potential use of repeated lateral flow tests to reduce the duration of quarantine and improve compliance was not investigated in our study. Future studies can consider evaluating the effect of this strategy on patient-important outcomes.A previous study reported that the transmissibility of asymptomatic cases may be significantly lower than that of symptomatic cases.Healthcare public policy decisions must rely on the best evidence, even if that evidence is of very low quality. Recommendations regarding isolation after COVID-19 diagnosis, because of their major implications for large numbers of people, represent a compelling example. Despite limitations of the evidence regarding the magnitude of hospitalisation resulting from 5 versus 10 days of isolation, because of the moderate credibility of subgroup analysis regarding duration of test positivity related to symptomatic status, there is a high likelihood that shorter isolation will result in appreciably less hospitalisation in the asymptomatic than the symptomatic patients. The WHO panel using the results of our work was therefore able to recommend 5 days of isolation for asymptomatic patients and 10 days for symptomatic patients.Our studies identify major gaps in the evidence regarding an optimal isolation period. Compelling evidence regarding optimal isolation will require conduct of randomised controlled trials. Future clinical studies could focus on patient-important outcomes  and test important subgroup hypotheses such as the variant of virus, disease severity, symptom status, vaccination status, immunosuppression status, and co-interventions.Our findings show that a 5-day isolation may result in minimal hospitalisation or death as a result of spread of COVID-19 for asymptomatic patients; the same may not be true for symptomatic patients. Removing isolation based on a negative antigen test is likely to shorten the average isolation period, possibly without negative consequences on onward transmission. Providing higher certainty evidence on the impact of alternative isolation strategies will require future studies using robust designs.YG, GG, and QH conceived and designed the study. YG and YZ screened and selected the articles. YG and YZ extracted the data and assessed the risk of bias. YG, XZ, and QH led the development and analysis of the model. GG supervised the data analyses. YG and QH rated the certainty of evidence. GG provided methodological support. YG, YZ, XZ, GG, JT, and QH interpreted the data. YG and QH drafted the manuscript. All authors reviewed the manuscript and approved the final version of the manuscript. YG and QH accessed and verified the underlying data. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.Data in this systematic review with meta-analysis are extracted from published studies available on the internet. All processed data are presented in this article and the appendix.We declare no competing interests.


The covid-19 pandemic has highlighted the role of living systematic reviews. The speed of evidence generated during the covid-19 pandemic accentuated the challenges of managing high volumes of research literature.In this article, we summarise the characteristics of ongoing living systematic reviews on covid-19, and we follow a life cycle approach to describe key steps in a living systematic review.n = 46, 47%) or the prevalence of associated conditions or risk factors . The scopes of several reviews overlapped considerably. Most living systematic reviews included both observational and randomised study designs . Only one-third of the reviews has been updated at least once . We address practical aspects of living systematic reviews including how to judge whether to start a living systematic review, methods for study identification and selection, data extraction and evaluation, and give recommendations at each step, drawing from our own experience. We also discuss when it is time to stop and how to publish updates.We identified 97 living systematic reviews on covid-19, published up to 7th November 2022, which focused mostly on the effects of pharmacological interventions (Methods to improve the efficiency of searching, study selection, and data extraction using machine learning technologies are being developed, their performance and applicability, particularly for reviews based on observational study designs should improve, and ways of publishing living systematic reviews and their updates will continue to evolve. Finally, knowing when to end a living systematic review is as important as knowing when to start.The online version contains supplementary material available at 10.1186/s13643-023-02325-y. A living systematic review is a systematic review, which is ‘continually updated, incorporating relevant new evidence as it becomes available’ . ResearcThe speed and sustained accumulation of published research about SARS-CoV-2 and covid-19 since the beginning of 2020 are unprecedented  and the prevalence of SARS-CoV-2 or covid-19-associated conditions or risk factors . Twenty-eight (29%) living systematic reviews included only randomised controlled trials, 22 (23%) reviewed only observational studies, and 45 (46%) reviewed both observational and randomised controlled trials. There were considerable overlap in the scopes of some studies. For example, four reviews focused on the diagnostic accuracy of rapid antigen tests, four on the effectiveness of vaccines, three on long-term symptoms of covid-19, and two on transmission of SARS-CoV-2 from mother to child. The studied populations were mainly people with suspected or diagnosed covid-19 or long COVID . They were mostly groups of any ages , which included studies on hospital patients (n = 23). Studies on adults only  included hospital patients (n = 13) and healthcare workers (n = 5). Most living systematic reviews had published a protocol before the first publication of the review , and most had at least one version published in a peer-reviewed journal .To summarise the status of living systematic reviews about SARS-CoV-2 and covid-19, we searched titles of records in the World Health Organization COVID-19 Database  using thUpdating with new evidence is a core principle of living systematic reviews . From JaThe workload for living systematic reviews depends on the review question, the eligible study designs, and the amount of underlying evidence. Review questions that do not restrict their search by study design or rely entirely on observational study designs, such as prevalence or aetiology studies, require more work at the early stages of the review than questions about interventions. One reason is that randomised trials are tagged in databases such as PubMed, there are validated search filters to find them, and guidelines that ensure that important items are reported. Indexing and reporting of observational study designs are less consistent, and authors may use different terms to describe the same approach . A seconWe summarise the steps in the life cycle of a living systematic review in Fig. The core team should coordinate the tasks of the review team, which includes anticipating and managing changes in workload, workflow, and team composition. At least one core team member should have sufficient programming skills to automate steps in the workflow where possible. In our case study, a core review team of seven became overwhelmed when the number of new hits to be screened increased Table . Growth Defining eligibility criteria for authorship is an essential task for the core team at the start of the review process, who should agree the policy in advance with the review team, including crowdsourced members. In our review, levels of contribution and availability changed during and between updates. Team members who fulfilled the criteria for authorship were co-authors of the relevant publication. We created lists of contributorship  in whichA protocol for a living systematic review is also a living document, which should reduce potential biases and avoid posthoc decisions , 18, 30.https://covid-19.cochrane.org/). We used the COAP living evidence database, a database aggregator .Additional file 1. Summary of methods used in a review of living systematic reviews on covid-19.Additional file 2. Living systematic reviews on covid-19 identified in the World Health Organization COVID-19 Database from January 2020 to February 2022, ordered alphabetically by first author.Additional file 3. Training materials for voluntary team members in the living systematic review.


L1000CDS2 tools. In NPS, we discovered 6 genes with changed splicing and 40 differentially expressed genes (DEG) that yielded 88 altered pathways. Blood samples yielded 15 alternatively spliced genes. Although the unpaired DEG analysis failed, pairing identified 78 genes and 242 altered pathways with meaningful clinical interpretation and new candidate drug combinations with up to 65% overlap. Metagenomics analyses showed SARS-CoV-2 dominance during and after the acute infection, with a significant reduction in NPS . Even though both NPS and BL give meaningful insights into expression changes, this is the first demonstration of how the power of blood analysis is vastly maximized by pairing. The obtained results essentially showed that pairing is a determinant between a failed and a comprehensive study. Finally, the bioinformatics results prove to be a comprehensive tool for full-action insights, drug development, and infectious disease research when designed properly.Previous transcriptome profiling studies showed significantly upregulated genes and altered biological pathways in acute COVID-19. However, changes in the transcriptional signatures during a defined time frame are not yet examined and described. The aims of this study included viral metagenomics and evaluation of the total expression in time-matched and tissue-matched paired COVID-19 samples with the analysis of the host splicing profile to reveal potential therapeutic targets. Prospective analysis of paired nasopharyngeal swabs (NPS) and blood (BL) samples from 18 COVID-19 patients with acute and resolved infection performed using Kallisto, Suppa2, Centrifuge, EdgeR, PantherDB, and  Accomplishing scientific achievements, such as pathogen identification and vaccine synthesis, were priority goals due to the heavy burden on health systems and the economy. Still, further efforts are necessary to understand the complex interactions between the host and severe acute respiratory coronavirus 2 (SARS-CoV-2). Although COVID-19 apparently shares numerous clinical manifestations with other common respiratory viral infections, a significant peculiarity of SARS-CoV-2 infection has been observed over time [During the current coronavirus disease-19 (COVID-19) pandemic, over 768 million infected people were registered, of which even 6.9 million ended fatally, ver time ,5,6. AllThe integrity of the nasal microbiome and virome may also be disturbed by an exogenous infective stressor such as SARS-CoV-2, leading to upregulation of the host innate immune system, activation of dormant pathogens, and establishment of microbial nasal mucosal host gene patterns ,9. To daAs a primary site of infection pathogenesis, local nasal expression is more COVID-19-dependent and specific. So far, transcriptome profiling studies have shown significantly upregulated genes and biological pathways altered during acute infection, such as proinflammatory cytokines, chemokines, enzymes in neutrophil-mediated immunity, and several IFN-stimulated genes ,14,15,16It could be observed that previous research has not yet examined and described changes in the transcriptional signatures during a defined time frame. This, in particular, implies considering paired samples related to acute and resolved infection because otherwise, the interpretation of human expression may vary . Moving p = 0.019), indicating a significant reduction in the viral RNA abundance at the control stage. Summation was attempted for all the phages and multiple bacterial taxa, but no significant differences were achieved.Metagenomic alignment of 36 nasopharyngeal swab samples yielded a total of 3772 species, out of which 2699 had unique mappings. After the analysis of unique reads, only 3 species that belonged to different assemblies of SARS-CoV-2 and SARS-CoV were statistically significantly different between cases and controls . Considering all reads (unique and multi-mapped), no individual species showed statistically different abundances. Still, the cases’ mean log-transformed value was bigger  downregulated . NPS samBased on protein–protein interactions, there are three clusters of genes without interconnections . The larFor the three successful design-tissue combinations , we obtained significant results of pathway analysis for three ontologies—cellular components, biological processes, and molecular functions. The potentially asymmetric upregulation at the individual gene level is validated at this step. Molecular function pathways for BL samples  show clip-value. Clustered visualization shows that most single substances primarily affect the genes from the immunoglobulin superfamily (IG*)  in our list, we suspected a versioning annotation problem and repeated the analysis without the histone genes. The top-ranking substance remained the same, but the score increased to 0.47 , and thely (IG*) .AS analysis events and isoforms in the independent design for two types of tissues are shown in To date, published studies have focused only on local nasal or systemic gene expression in acute COVID-19. It was unknown if there were any changes when the acute illness resolved. Taking this hypothesis into account, we examined gene expression profiles in paired designed samples of total RNA in acute and resolved SARS-CoV-2 infection to assess complete characterization and time-related differences of host-viral relationship in COVID-19 patients. The pathways that were mostly enriched were largely ones that control infection and inflammation, smell function, as well as a major portion of the receptor signaling and oxygen binding pathways. Besides identified biomarkers, this study revealed new drug co-targeting pathways.Considering that the blood transcriptome reflects signals from different tissues and host biochemical processes, dispersion in RNA quantification could weak and mask many of those tissue-specific signals . MoreoveUsing sample pairing design in this study increased the number of significant genes from 2 to 78, enabling a meaningful pathways analysis and functional/clinical validation of the project. Although this design represents a simple method for increasing power when interpersonal variability is large, genomic studies rarely take advantage of it when it comes to transcriptome analysis. Single-cell sequencing could be done at multiple time points to characterize cells in both time and space, but we strive to measure the improvement when applied in bulk sequencing for the characterization of systemic effects . The paip = 0.019), indicating a significant reduction in the viral RNA abundance at the control stage.The enrichment analysis has shown down-regulation of olfactory receptor, G protein-coupled receptor activity, and up-regulation of cytokine receptor binding in the nasal epithelium of paired samples, of which the first two were also down-regulated in paired blood samples. Olfactory dysfunction is a common symptom experienced by almost 53% of COVID-19 patients and affects approximately 7% of the COVID-19 convalescents ,25. TherTranscriptionally, our samples are characterized by the enrichment of pathways involved in cytokine receptor binding in nasal epithelium. After the appearance of SARS-CoV-2, cytokine storm was indicated as a main pathogenetic factor in COVID-19 . A largeIFI27, interferon alpha inducible protein 27, transcription has recently been a proven predictor for COVID-19 outcomes . A higheViruses manipulate cell cycle progression to generate resources and conditions favorable for viral production. Still, the effect of SARS-CoV-2 on cell cycle progression remains largely unknown . TherefoThe greatest significance of our survey is that it reveals new co-targeting pathways of high potential for the success of synergistic drug action of nocodazole and BRD-K12184916. Even 65% of genes of acute COVID-19 patients are included in described co-targeted pathways: microtubule cytoskeleton organization and condition of hypoxia. These gene co-targets could serve as a promising step toward the identification of additional drug options, especially because some of them are already in use in other indications. The cytoskeleton, in particular, microtubules, have an essential role in cell mitosis, organization of cytoplasm, and controlling of cell movement, cell signaling, and trafficking of organelles. Their disruption leads to cell cycle arrest and loss of cellular architecture . TherefoThe main limitation of the study was the sample size and the lack of clinical metadata that would enable further clinical correlations and stratification with transcriptomic biomarkers. The sample size was sufficient for the paired analysis performed without additional covariates but would be insufficient for investigating a subsample defined with the additional clinical data. As a consequence, even with strong statistical signals arising from the transcription of individual genes such as IFI27, we were unable to extrapolate their prognostic value to a broader clinical context. On the other hand, the study managed to unify the molecular mechanisms regardless of the differences in the clinical presentation of the disease, which could be considered a result that overcomes the described limitations.Metagenomics analyses from the total RNA are susceptible to bias from existing fragments and show positive results even when conventional testing methods give a negative signal. However, the coexistence of other RNA viruses was not shown during the active disease or in the convalescence period.Designing genomic research on a relatively novel subject harbors difficulty in formally estimating the required sample size and the proper design since maximizing the study power increases the probability of its success. Nasopharyngeal swabs are viable targets for both host and viral expression studies. Although they do not require sample pairing, those samples give limited insight into the systemic events. On the other hand, the analysis of blood samples benefits immensely when a sample pairing strategy is applied. In particular, the unpaired expression analysis performed in our research essentially failed to pinpoint significant changes, but the pairing successfully elucidated different pathways as well as the potential therapy targets with high concordance to clinical insights. Thus, the obtained results essentially showed that pairing is a determinant between a failed and a comprehensive study.We performed a prospective analysis of nasopharyngeal swabs (NPS) and blood (BL) samples collected from 18 COVID-19 patients infected between December 2020 and April 2021. The patients were all recruited in the acute phase of COVID-19, during the 7-day period from the onset of the disease. Among 18 patients, 12 were hospitalized but with different disease severity, and 6 non-hospitalized individuals were tested due to mild symptoms and suspicion of COVID-19. Hospitalized patients were treated at the University Hospital Center Dr Dragisa Misovic, Belgrade, and the Serbian Institute of Occupational Health, Belgrade. Patients with mild symptoms were tested on request in the Laboratory of Molecular Microbiology, Institute for Biocides and Medical Ecology, Belgrade.Both NPS and BL samples were collected from every participant immediately after inclusion in the study, and they were defined as “cases.” Their samples were paired during the second sampling  after resolving the SARS-CoV-2 infection , and then they were defined as “controls”. At the moment of the first sampling, according to the set inclusion criteria, nasopharyngeal swabs all tested positive for SARS-CoV-2 RNA by Real-Time PCR. On the other hand, paired nasopharyngeal swabs taken after resolving the acute infection all tested negative for SARS-CoV-2 RNA by the same methodology.RNA isolation and SARS-CoV-2 detection was performed in the Laboratory of Molecular Microbiology, Institute for Biocides and Medical Ecology, Belgrade. RNA extraction from 200 μL of whole blood or 500 μL of viral transport medium, in which nasopharyngeal swabs were placed, was carried out using RNeasy Mini Kit . Real-time PCR to confirm SARS-CoV-2 positivity was routinely performed from 5 μL of eluted RNA using GeneFinderTM COVID-19 Plus RealAmp Kit  following the manufacturer’s protocol. Quant StudioTM 5 Real-Time PCR Instrument  was used for the amplification and detection of viral RNA. All eluates were stored at −80 °C until shipment to the other laboratory for the NGS analysis.Commercial sequencing was carried out at Novogene Bioinformatics Technology Co., Ltd., in Beijing, China. Messenger RNA was purified from total RNA using poly-T oligo-attached magnetic beads after rRNA removal . After fragmentation, the first strand of cDNA was synthesized using random hexamer primers, followed by the second strand of cDNA synthesis . The library was ready after end repair, A-tailing, adapter ligation, size selection, amplification, and purification. Paired-end sequencing of 150 bases each was performed on Illumina NovaSeq 6000. QC was done according to the sequencing provider’s specification, and 6 samples of blood with their pairs were removed from the blood batch of samples. The total number of paired samples was 18 pairs of nasopharyngeal swabs and 12 samples of blood. The average base quality Phred score was above 30 at all locations in all samples.Both nasopharyngeal and blood samples are quantified in an identical manner using Kallisto 0.44  for pseuL1000CDS2 web service to find the chemical perturbagens with the expression pattern opposite to that of our disease. The direction of change was taken into account without the numerical values for easier interpretation of the output. Genes without an HGNC name necessary for this step were manually added from the latest version of the Ensembl database. Combinations of two perturbagens were also included in the outputs. The ranking score used was the overlap ratio, and top-scoring hits were visualized with web Clustergrammer.The significantly affected genes from DEG analysis were separated into two gene sets according to the direction of change and analyzed with the p-value calculation without using a delta PSI threshold. Due to the empirical nature of the calculation and lack of linear models, the samples were treated as unpaired .TPM results from Kallisto quantification were pooled and processed for the detection of alternative splicing (AS) changes using the tool Suppa2 . To matcMetagenomic analysis was performed by aligning all the samples read-wise to the joint human-bacteria-virus-SARS-CoV-2 reference using a centrifuge. The numbered of mapped reads was scaled with the total number of reads in the sample. The difference in medians between case and control samples was performed using the median test that ignores pairing. The median test was used instead of the Wilcoxon sign rank due to the immunity to a large number of ties in most samples. Multiple testing correction was performed using the Bonferroni method. All 95 columns with different assemblies of SARS-CoV-2 were summed and log-transformed, and the difference in abundances was tested using the t-test for dependent samples.