The mechanical behavior of nanostructures is known totransitionfrom a Hall-Petch-like “smaller-is-stronger” trend,explained by dislocation starvation, to an inverse Hall-Petch “smaller-is-weaker”trend, typically attributed to the effect of surface diffusion. Yetrecent work on platinum nanowires demonstrated the persistence ofthe smaller-is-stronger behavior down to few-nanometer diameters.Here, we used in situ nanomechanical testing inside of a transmissionelectron microscope (TEM) to study the strength and deformation mechanismsof platinum nanoparticles, revealing the prominent and size-dependentrole of surfaces. For larger particles with diameters from 41 nm downto approximately 9 nm, deformation was predominantly displacive yetstill showed the smaller-is-weaker trend, suggesting a key role ofsurface curvature on dislocation nucleation. For particles below 9nm, the weakening saturated to a constant value and particles deformedhomogeneously, with shape recovery after load removal. Our high-resolutionTEM videos revealed the role of surface atom migration in shape changeduring and after loading. During compression, the deformation wasaccommodated by atomic motion from lower-energy facets to higher-energyfacets, which may indicate that it was governed by a confined-geometryequilibration; when the compression was removed, atom migration wasreversed, and the original stress-free equilibrium shape was recovered. It is well establishedthat decreasing the size of a structure increases its strength byreducing or eliminating defects and defect sources, giving rise tothe “smaller-is-stronger” trend.10 Below the size scale of a fewhundred nanometers, surface nucleation of dislocations11 becomes the dominant deformation process inpristine nanostructures14 as well as twinned and multimetallicstructures,15 resulting in a size-independenthigh-strength plateau.18 This surfacenucleation has been extensively studied in nanowires and can be describedas a stress-dependent thermally activated process,12 where the activation barrier is highly sensitive to thesurface state, with surface steps and terraces lowering the yieldstrength.21Metal nanoparticles are used in technologyapplications, such assensing,23 At sufficiently high homologous temperatures25 or ultrasmall sizes,25 surface diffusionis proposed to provide an alternative mechanism for shape rearrangementunder stress. This mechanism has been described using the frameworkof Coble creep25 with the stress proportionalto strain rate and inversely proportional to the cube of nanoparticlesize.26 This so-called diffusive plasticity manifests as a homogeneous, liquid-like response to loading, eventhough the nanoparticle or nanowire remains crystalline.27 Furthermore, structures deformed in this way can spontaneously recovertheir original shape after compression as observed in the bluntingof fractured Cu nanowires24 and liquid-likedeformation of 10 nm Ag particles.26 Thebehavior is often called pseudoelasticity or shape recovery. However,unlike investigations showing shape recovery by the reverse motionof defects , surface-diffusion-induced shape recovery ismainly attributed to the curvature-driven surface diffusion of atoms.24It was later demonstrated that plastic deformationcan occur inthe absence of defect-based mechanisms, with shape change insteadoccurring through long-range atom migration.30 For Ag, that work showed that the traditionalHall-Petch-like trend continued until reaching peak strength at nanowirediameters of approximately 15 nm, below which an inverse Hall-Petchtrend was observed. By contrast, the results for Pt demonstrated thatthe Hall-Petch-like trend persisted at the very smallest sizes. Ininterpreting these results, the study attributed the weakening ofAg not to the long-range atom migration assumed by the Coble-creep-likemodel but rather to surface-diffusion-induced acceleration of thesurface-nucleation of dislocations. The authors referred to this as diffusion-assisted dislocation nucleation. Smaller-diameterwires exhibited faster diffusion which increased the chance of nucleation,and thus the strength decreased. However, this smaller-is-weaker trendnever appeared in Pt, which the authors attributed to slower diffusiondue to its high melting temperature. Large-scale deformation via surfacediffusion was not observed in any of the wires, and all deformationwas attributed to displacive mechanisms that were assisted by diffusion.This agrees with other findings suggesting defect-based plasticityeven at the smallest sizes in gold.31Very recently, an in situ TEM investigationmeasured the failurestress of Ag and Pt nanowires and observed their deformation mechanisms.Given the discrepancies between the expected Coble-creep-like deformationand the observed diffusion-assisted displacive deformation in platinumnanowires, the purpose of this investigation was to interrogate thecompeting effects of surfaces in nanoparticle deformation: accommodatingshape change through atomic migration and facilitating surface nucleationof dislocations. To accomplish this, in situ compression tests wereperformed on Pt nanoparticles with diameters ranging from 41 to 6nm. The tests were performed in a TEM using an atomic-force-microscopyprobe as the indenter see  enablingThe mechanical behavior of the nanoparticles is shown using true-stress–true-straincurves in Video S1.The particle was linearly compressed up to a peak stress of 3.1 GPa(point (c) in 34 and earlier work on platinum35 and palladium36 nanoparticles have shown that defect plasticityin face-centered cubic (FCC) nanostructures proceeds via Shockleypartial dislocations that leave behind stacking faults. However, thepresent testing was optimized for load measurement and the specificdefects were not identified. The yield strength of this particle,3.1 GPa, was much higher than that of bulk Pt (of order 100 MPa),but significantly lower than Pt’s theoretical strength of 9.5GPa17 and previous measurements of nanowiresin the range of 4.5–9 GPa.27 In the end, this particle failed inhomogeneouslyand separated with part of the particle attached to the indenter.While the separation plane appears to be parallel to the indentersurface, our prior work on similar particles indicates failure alongthe expected Schmid-factor plane;35 therefore,we attribute the present shape to post-test flattening when the topportion of the particle slid off the lower portion and hit the substrate.The majority of the larger particles failed along an inclined plane,similar to those shown in Supporting Information Section S2.To understand the distinct behavior of these twostress–straintrends, we examined a representative particle from each category in detail 2. FigureVideo S2). Immediately upon contact, the particleexhibited a shape change  and is discussed further in a latersection.The 8.6-nm nanoparticle exhibited very differentbehavior, showingno well-defined yield strength and exhibiting dramatic plastic flowat relatively low stress levels (<0.5 GPa). The morphological evolutionof this particle is shown in e change 2f,g, shoFigure S8. The behavior observed in displacive deformation (blue squares in Videos S1 and S4),rather than the liquid-like deformation associated with the Coble-creep-likemodel.26 The observed behavior is alsoin contrast to the work of Wang et al.,30 which showed Hall-Petch-like strengthening for Pt nanowires thatpersisted down to 5 nm. This difference in behavior from Wang et al.30 is attributed to differences in sample geometry.In the experimental and simulated tensile testing of Wang, the nanowireshad straight sides  decreased monotonically with decreasing size. A representativevalue of nanoparticle strength, the stress at 10% strain, is shownin 37 and also modifies the degree of spatial inhomogeneity ofstress.38 Particle shape modifies variousfactors, including stress concentrations at corners,39 and the out-of-plane shape of FCC structures can influencewhich types of defects are favored.40 Moreover,the TEM only provides a side-view image of the particle, and therefore,an assumption was made of approximately circular cross-section inthe out-of-plane direction. The second factor contributing to thescatter in the measured data is the inherent stochasticity of dislocationnucleation that has been observed in other investigations.12 The strength is often represented by using aprobability density function41 reflecting the probabilisticnature of the thermally activated nucleation event.There is significant scatter in the strengths ofthe larger particlesdominates the behavior. Given the wide range of particle shapes tested,the most consistent effect of decreasing diameter is an increase insurface curvature, suggesting that the curvature of the particle isgoverning strength in this regime. This is consistent with prior calculations44 and simulations45 showing the importance of the angle of a corner on dislocation nucleation;sharper angles lead to smaller dislocation line lengths of the embryonicdislocation and thus significantly reduced barriers to nucleation.Despitethe scatter in the data, the decreasing trend of strengthwith decreasing size in the displacive regime reveals the dominanteffect of surface curvature on the deformation. The surface nucleationof dislocations has been shown to be sensitive to particle size,49 and thus higher homologous temperature.The semiempirical thermodynamic model by Kim and Lee50 (Supporting Information Section S5) shows that the predicted change in melting temperature is modest.For example, when the nanoparticle diameter shrinks from 30 to 20 nm, the melting temperature changesfrom 2005to 1947 K. However, the present investigation could not distinguishwhether the reduction in strength was caused by a lowering of the barrier to dislocation nucleation or by increased atomicdiffusion. Either way, the results show a clear size-dependent weakeningas particles shrink from 41 nm to approximately 9 nm, which is suggestedto arise due to increased surface curvature that accelerates the surface-nucleationof dislocations.Smaller particles and increased surface curvature are also associatedwith accelerated atomic diffusion because of the Gibbs–Thomsoneffect on chemical potential, which leads to the depression of themelting pointParticles withsizes below 9 nm (red circles in Video S4), well beyond the theoretical elastic strain limit in crystallinenanomaterials.52 During testing, there were noinhomogeneous features or changes in contrast observed that wouldindicate displacive deformation; however, we acknowledge that thebright-field imaging used in this testing is less sensitive to thesechanges compared to dark-field. Instead of abrupt changes in particleshape, a significant shape change occurs at the surfaces adjacentto the indenter surface. Then, after removal of the compression, thenanoparticles recover their original shape, including the surfacefacets, within a few seconds. This shape recovery of small particleswas not associated with plastic mechanisms29 but instead occurs by surface rearrangement, as has been observedin lower-melting FCC metals.31To identify the mechanisms of atom migration,a modified test configuration was used (see Video S4) shows that the surfaceis composed of atomic steps which dynamically change via a seriesof atom-hopping events (see Supporting Information Video S4). Three surface steps are specified by numbers in Section S6) yields a diffusion constant of 2.8× 10–20 m2/s, which is in order-of-magnitudeagreement with the value computed by Zhong et al.53 This therefore confirms the slow diffusion kinetics ofhigh-melting-temperature platinum, even while demonstrating that large-scalehomogeneous deformation is clearly accommodated by surface atom migration.Using real-time high-resolution images, the particle’ssurfacewas traced to track the changes in the initial {111} surface facets. The nanoparticle-decorated wedgeswere transferred to a commercial in situ TEM nanomanipulator  as shownin 54 spring constant k. Two different types of AFM probeswere used: one was composed of silicon with a native oxide coating,and the other was also silicon but with a surface coating of diamond-likecarbon. The overall shape of the probe was pyramidal but with a hemisphericalapex radius that was larger than the nanoparticles being tested. Thecompression tests were performed in a TEM  at an accelerating voltage of 200kV. The tests were performed at a constant displacement rate of 0.5nm/s. The applied force was then computed using Hooke’s law, F = kx, where x is theprobe–tip displacement, extracted from post-test video analyses(Section S8). The true stress was computed as the instantaneous force over theinstantaneous contact area, which was computed from a measurementof the contact diameter (A = πD2/4) between the indenter and the particle. Prior workby the authors on similar particles has shown that there can be spatialinhomogeneities in stress depending on shape and orientation,38 but the contact stress is considered to be areasonable characteristic value for representing the stress in theparticle.Bare platinum nanoparticles were synthesizeddirectly on siliconwedges using either wet impregnation (WI) . In this work, analysis was performed on the loadingphase of the particles only (2, whichwas sufficiently low to be excluded as a major factor impacting theshape evolution of particles.53The real-time video was also used to extract theinstantaneousshape and size of the particle 2 and 4. les only 5c. To liTwo test configurationswere used. For most of the tests 1–3, the


The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were higher for the study group on postoperative days 9 and 12 than for those in the control group (p < 0.05). However, D-dimer levels were not significantly different between the two groups. We should cautiously consider that COVID-19 infection within 1 week after TKA may be associated with increased ESR, CRP levels, and length of hospital stay, but they are not associated with the worsening of early clinical outcomes or the occurrence of complications.Recent studies have reported the impact of previous COVID-19 infection on the early clinical outcome after total knee arthroplasty (TKA). However, the timing of infection before the surgery was not constant and a study on patients with COVID-19 infection within 1 week after TKA is lacking. This study aimed to determine the effect of COVID-19 infection within one week after TKA on the postoperative outcomes and to compare the early clinical outcomes to those who were not infected with COVID-19 before and after surgery. No significant differences were observed between the two groups in terms of clinical outcomes or complications. The length of the hospital stay (LOS) was significantly longer for the COVID-19 group than for the non-COVID-19 group ( The SARS-CoV-2 COVID-19) virus has led to an unprecedented cancellation of elective surgeries and it is continuously challenging the previously established standards of healthcare institutions 9 virus h. HoweverThe present study retrospectively collected clinical data from consecutive patients who underwent TKA at our institute between January 2021 and December 2022. All patients who had COVID-19 infection within 1 week after TKA were identified. Patients with a history of COVID-19 infection before TKA were not included. Those with a second knee in staged bilateral TKA and secondary osteoarthritis (OA) were also excluded to reduce bias. The exclusion criteria included the presence of major comorbidities, such as severe pulmonary disease, coagulopathy, and a history of VTE disease. The final study cohort included 21 patients with TKAs (the COVID-19 group). To reduce the selection bias and potential confounding effects, a matched comparison cohort was subsequently created as the non-COVID-19 group. In the database of 422 TKAs conducted, we identified a comparison cohort with a ratio of 1:2. The patients were matched for sex, age, unilateral surgery, prosthesis type, same surgeon, same operating unit and surgical timing, and American Society of Anesthesiologists (ASA) score; we obtained 42 patients who underwent TKA and did not have a history of COVID-19 infection (the non-COVID-19 group) . The stuAll the operations were performed by a single senior surgeon at a single institution. All the patients were managed using the same protocol. A pneumatic tourniquet was applied during the operation and deflated before wound closure. Cemented components were used in all the cases. The prostheses used were the posterior-stabilized Anthem System  in 41 knees and the Lospa system  in 22 knees. There were 15 out of 41 cases with the Anthem System, and 6 out of 22 cases with the Lospa System of COVID-19 infection 1 week after TKA. The patella was not resurfaced in any of the cases . A suctiRegardless of clinical signs, cases in which infection was confirmed according to diagnostic criteria were defined as COVID-19 infection . In the COVID-19 patients presenting with fever (37.5 °C or higher) and/or respiratory symptoms  within 14 days of visiting China  or other COVID-19-affected countries (as listed on the WHO website), we implemented a treatment protocol of administering intravenous Remdesivir for a duration of 3–5 days [The American Knee Society (AKS) score and Western Ontario and MacMaster (WOMAC) were used for clinical evaluation ,21. ReguBlood samples were obtained before surgery and on the first, second, fifth, ninth, and twelfth postoperative days (POD), from the patients who underwent unilateral TKA. D-dimer levels were measured from the samples collected between preoperative screening day 7 and 14 and on the twelfth postoperative day. The hematologic parameters compared between the two groups were hemoglobin (Hb) levels, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, and D-dimer levels. CRP levels were measured using the turbidimetric immunoassay on the COBAS c 702  and the normal range was set to less than 0.4 mg/dL. ESR was measured using a photometric kinetic analysis of capillary-stopped flow on the Test-1 system ; the normal range for the laboratory at our hospital was less than 20 mm/h. D-dimer levels were measured using a Stago STA-R MAX  that used a turbidimetric immunoassay and the normal range was less than 490 ng/mL.t-test was used to compare the continuous data. A chi-square or Fisher’s exact test was used to compare categorical data. The statistical significance was set at a two-sided p-value of less than 0.05. All analyses were performed using SPSS software version 23  and continuous data are expressed as the mean± standard deviation. Sample size calculations were performed using R . The sample size was evaluated based on the measured primary outcome and was calculated to be 13 knees in the study group and 26 knees in the control group, assuming 80% power, an alpha error of 0.05, and an enrollment ratio of 2. A difference of 26% in the clinical scores was selected based on calculations of effect sizes from values of the postoperative clinical score reported in a retrospective study of clinical outcomes in patients with TKA [No significant demographic differences were observed between the COVID-19 and non-COVID-19 groups, except for the length of hospital stay (LOS) . The meaThe mean preoperative Hb, ESR, and CRP levels did not differ significantly between the groups. The levels for all three serum tests, preoperatively and on POD 5, 9, and 12, are presented in n = 1) in the COVID-19 group and gastroenteritis (n = 1) in the non-COVID-19 group.No significant differences were observed in complications, such as hemarthrosis, stiffness, wound dehiscence, PJI, pneumonia, DVT, and PE, between the two groups . The 90-The main finding of the present study is that COVID-19 infection within 1 week after TKA does not affect early clinical outcomes and complications. However, it may be associated with increased ESR and CRP levels and length of hospital stay, but they are not associated with worsening early clinical outcomes and the occurrence of complications. Considering the potential systemic effects of COVID-19 on patients, it is important to acknowledge the findings of our study, which indicate that the occurrence of infection, pneumonia, and other complications are similar between patients with and without a history of COVID-19 infection. Although further research is necessary to establish a causal relationship, these findings deserve careful consideration by physicians who are providing care to TKA patients with a history of COVID-19 infection. Furthermore, it is important to recognize that the various COVID-19 variants and sub-variants could potentially influence the disease’s impact on patients and subsequently affect outcomes such as pneumonia and DVTs.COVID-19 created an unprecedented challenge for elective orthopedic care . SeveralESR and CRP are acute-phase reactants that reflect a measure of the acute-phase response after a stimulus and have been widely used to monitor the postoperative course after TKA because of their advantageous characteristics, including a rapid increase in concentration, relatively short lag time, and cost-effectiveness ,32,33. PSun et al.  reportedD-dimer is a widely available serum biomarker known for its diagnostic utility for fibrinolytic activities in thromboembolic events ,39. SincThis present study found that patients who had a COVID-19 infection within 1 week after TKA did not exhibit significantly higher rates of postoperative complications compared to the non-COVID-19 group. Specifically, there were no significant differences in the occurrence of hemarthrosis, stiffness, wound dehiscence, pneumonia, PJI, and 90-day readmission between the two groups. These findings are important as they suggest that the timing of COVID-19 infection in relation to TKA does not significantly impact the occurrence of common complications associated with the surgery. Patients undergoing TKA may vary in age and have different comorbidities that can influence the likelihood of unplanned hospital readmissions following surgery. Therefore, it is crucial for healthcare providers to identify patients who are at higher risk for such complications in order to minimize their occurrence and evaluate outcomes based on risk stratification. According to a study by William et al. , the reaDespite these informative results, our study has some limitations. First, it was a retrospectively study and a major challenge was obtaining the largest dataset possible to fully validate our hypothesis. However, the number of patients included in this study surpassed the requirement outlined in the power analysis. Considering the rare incidence of COVID-19 infection within one week after TKA, it would be difficult to conduct a prospective study with a more sufficient number of patients. Second, two different prostheses were used. However, our study was conducted by a single surgeon at a single institute and we used posterior-stabilized knee designs in all the patients without patella resurfacing to reduce bias. Finally, we acknowledge that the discrepancy in the length of hospital stays for the non-COVID-19 group can be attributed to the necessity of extended hospitalization for patients with COVID-19. Nevertheless, our study has important strengths. There have been no reports of patients with COVID-19 infection during the recovery period within 1 week after TKA. As mentioned, the timing of infection before surgery was not constant in previous studies. The results under the precise conditions of this study will help healthcare professionals to evaluate the progress of rehabilitation. They can determine if the patient is responding well to physical therapy and rehabilitation exercises, and make any necessary adjustments to the treatment plan.We should cautiously consider that COVID-19 infection 1 week after TKA may be associated with increased ESR and CRP levels and length of hospital stay, but they are not associated with a worsening of early clinical outcomes or the occurrence of complications. This study reports that having a history of COVID-19 infection should not significantly increase our concern of their perioperative risk. Therefore, if treated according to the established protocol, we can achieve outcomes as favorable as those for patients who have not had COVID-19 infection.


The article questioned the utilization of mesh-reinforced cruroplasty in the early- and medium-term follow-up since similar recurrence risk ratios (RR) were found between groups.We read the systematic review and meta-analysis by Angeramo and Schlottmann.I2 = 40%) and late (I2 = 64%) recurrence while the leave-one-out sensitivity analysis did not reveal any significant changes in the overall effect. Diverse inclusion criteria, hernia size, surgical indications, and definition of recurrence were heterogeneous, while surgeon experience, mesh materials, shape, crural fixation, and type of fundoplication were assessed thus possibly explaining such a noteworthy interstudy heterogeneity. All these issues significantly limit the validity and robustness of the study, and suggest more pondered conclusions.We thank the authors for their contribution and attempt to clarify such an intriguing topic. However, we believe that there has been some data misinterpretation possibly leading to misunderstanding of outcomes. When assessing the RR for early (<6 months) and late (>6 months) recurrence, we found some incongruities between the data presented in the Forrest plot and the results reported in selected trials. This occurred because recurrence was not uniformly defined among trials and because the authors included patients lost at follow-up. This conceivably introduced an overestimation of the causative effect. Moreover, the related heterogeneity was significant for both early  and in heterogeneity . However, the one-leave-out sensitivity analysis showed that after exclusion of the study by Oor et al, the heterogeneity decreased to zero (I2 = 0.0%) . Remarkably, the pairwise analysis performed after the exclusion of the study by Oor et al showed a significantly reduced RR of recurrence for mesh-reinforced cruroplasty versus simple repair  . We performed random effect frequentist meta-analysis using the Inverse variance method, the restricted maximum-likelihood estimator for the between study variance τ2) and the Q-Profile method for confidence intervals. We considered a more homogeneous definition of recurrence among trials (both anatomic and symptomatic) and excluded patients lost to follow-up Fig. . Similar and the 4 Our data support previous studies that conveyed reduced risk for recurrence after mesh reinforced cruroplasty.6 At present, this topic remains open to debate and consensus is limited due to the complexity of factors involved in paraesophageal hernia recurrence and the lack of standardization of current surgical techniques.7 We believe that, in selected patients, use of a resorbable synthetic mesh as an adjunct to adequate distal esophageal dissection, standard cruroplasty, fundic mobilization, and posterior partial fundoplication has the potential to reduce early recurrence rates and improve quality of life outcomes.9The repair of the hiatus is a matter of intense discussion while the “ideal” method for crural repair is debated since the first description by Soresi.


Mounting evidence indicates increased risk of COVID-19 among healthcare personnel, but the evidence on risks in other occupations is limited. In this study, we quantify the occupational risk of COVID-19-related hospital admission in Denmark during 2020–2021.The source population included 2.4 million employees age 20–69 years. All information was retrieved from public registers. The risk of COVID-19 related hospital admission was examined in 155 occupations with at least 2000 employees  referenced to a group of mainly office workers defined by a COVID-19 job exposure matrix (N=369 341). Incidence rate ratios (IRR) were computed by Poisson regression.During 186 million person-weeks of follow-up, we observed 2944 COVID-19 related hospital admissions in at-risk occupations and 559 in referents. Adjusted risk of such admission was elevated in several occupations within healthcare , social care  and transportation . Most IRR in these at-risk occupations were in the range of 1.5–3. Employees in education, retail sales and various service occupations seemed not to be at risk.Employees in several occupations within and outside healthcare are at substantially increased risk of COVID-19. There is a need to revisit safety measures and precautions to mitigate viral transmission in the workplace during the current and forthcoming pandemics. The COVID-19 pandemic caused by SARS-CoV-2 virus posed a new and potentially fatal occupational hazard. Transmission of SARS-CoV-2 infection could be expected not only within households, and through private and public social contacts in leisure time, but also in the workplace – and particularly in jobs  that entail frequent close contact with other people or selective contact with infected individuals . TransmiIdeally, research into risks of COVID-19 by occupation would be based on cases ascertained through systematic prospective follow-up of large cohorts of workers, with regular ascertainment of symptoms, clinical signs, and polymerase chain reaction (PCR) testing. As that has not been feasible, researchers have been forced to use proxy measures of incidence based on: PCR testing –11, measWhile the majority of studies so far have focused on healthcare workers , 23–29, As yet, however, few studies have quantified differences in risk of severe disease across highly specific occupations. Among research priorities outlined in an editorial, identification of specific occupations at high risk of COVID-19 was considered of high value as preparation for future pandemics . The attThe aim of the current study was to systematically quantify the risk of COVID-19-related hospital admission among employees across all occupations with >2000 employees during the first two years of the pandemic. Hospital admission was considered a proxy for severe COVID-19. The study took advantage of access to updated information in a large nationwide cohort. We focused on hospital admission as an outcome to achieve greater statistical power than an analysis of mortality, and to avoid the possibility of bias from differential access to testing by occupation .The study cohort comprised all Danish employees aged 20–69 years at 1 January 2020 (N=2 451 542). It was identified from records in the Work Classification Module at Statistics Denmark, as a subset of the Danish Occupational Cohort with eXposure data (DOC*X) . Other pOccupation and industry codes are primarily provided by employing companies but other sources of information such as tax records, trade union membership, and educational records are also used by Statistic Denmark. This allowed assignment of job titles according to the Danish version of the International Standard Classification of Occupations (DISCO-08) , for 86%With one exception, it was not possible to infer missing DISCO-08 codes from known DB07 codes because individual DB07 codes are associated with a wide miscellany of DISCO-08 codes. However, as 75% of employees within ‘hairdressing and other beauty treatment’ (DB07 code 96.02.10) were hairdressers (DISCO-08 code 5141), all individuals with a missing DISCO-08 code within this industry (N=1135) were assigned the 5141 DISCO-08 code.Data on admission to hospital for COVID-19-related disease from 1 January 2020 through 14 December 2021 were obtained from a daily updated database with national coverage kept at Statens Serum Institut, Copenhagen. A hospital admission was defined as COVID-19 related if a SARS-CoV-2 PCR swab test was positive up to 14 days prior to admission, and if the hospital stay was >12 hours . An examination of ICD-10 diagnoses available from the National Patient Registry indicated that about 2.5% of cases using this definition were probably attributable to other causes such as psychiatric, traumatic, or obstetric disorders.a priori as occupations classified to the lowest level of potential occupational exposure to SARS-CoV-2 by an expert-rated COVID-19 JEM . The three largest job groups in the reference population were general office clerks, commercial sales representatives, and accounting associate professionals .The reference group was defined D-19 JEM . Eight dAn overview of the subsets of the study population is displayed in Using their unique personal identification numbers, we linked each cohort member with records in public registers hosted by Statistics Denmark to obtain information on a range of demographic, social and health variables at the end of 2019: sex, age, duration of education in years, country of origin, social position, household income, hospital admission for ≥1 of 11 chronic diseases during 2010–2019, geographical residential area and living in a municipality with a large city.From data on household members, we defined variables indicating the size of the household sharing the same residence. The number of family members (excluding the index-person), who had ≥1 PCR swab test during the second or third week before any particular week during follow-up, and the results of those tests, were retrieved from the national testing database, which by mid December 2021 included results of about 40 million PCR tests. Tests were available free of charge throughout the country from early on in the first epidemic wave. The 2–3 week interval was specified to account for incubation period and disease development before hospitalization2) were assigned by lifestyle JEM based on questionnaire information from several large random samples of the Danish population representative for 2010  with 95% confidence intervals (CI), were computed by Poisson regression applied to counts of COVID-19 hospital admissions and weeks at-risk for all covariate cross tabulations. Follow-up started in week 8 of 2020  and continued until (and including) week 50 of 2021 (the last week with available data on COVID-19 admissions). Follow-up was censored at the first of: COVID-19 related hospital admission (N=4416); death (N=2615); emigration (N=18 112); retirement (N=33 427); or week 50 of 2021.A power calculation based upon the outcome occurrence in the reference group indicated that a relative risk of 1.8 would be detectable in an occupation with 80% power at the 5% significance level if it included >2000 employees. Therefore, we report risk estimates for the non-referent occupations of this size or larger, while keeping all jobs regardless of size in the reference group. Occupations with ≤2000 employees and employees with missing DISCO-08 codes were analyzed as separate categories.Risk estimates by industrial sector. To account for possible differences between the same occupation in different industrial sectors – for instance cleaners in hospitals versus cleaners in office buildings and nursing aides in institutions versus nursing aides in private homes – we present occupational risk stratified by industrial sectors with more likely exposure to SARS-CoV-2. These industrial sectors were selected by an average COVID-19 JEM sum score >12 (the median) for industries classified at the 2-digit DB07 level. DB07 groups were pooled when appropriate, considering type of industrial sector . In few instances we deviated from the 4-digit DISCO-08 classification by splitting the 4-digit groups into 6-digit groups to distinguish more specific occupations (for instance day care assistants by age of the children taken care of) or to pool 4-digit groups into 3-digit groups to obtain sufficient sample size – for instance generalist and specialized medical practitioners or waiters/bartenders , while scoring low on other dimensions (for instance job insecurity). For that reason and to provide a full systematic quantification of occupational risk independent of industrial sector and COVID-19 JEM assessment, we estimated the risk for all non-referent occupations with >2000 employees at the 4-digit DISCO-08 level while keeping occupations with ≤2000 and employees with missing DISCO-08 data as separate categories.Adjustments. In all analyses, we first adjusted the risk estimate by sex and age, which are strongly related to both occupation and outcome . Secondly, we further adjusted for a fixed set of baseline variables according to the disjunctive confounder variable selection criteria .During 228.2 million person-weeks, we observed 4416 COVID-19 related hospital admissions peaking in weeks 12 and 50 of 2020, and week 47 of 2021 , but not in education, retail sales and a heterogeneous group of service jobs) .Within healthcare, eight of thirteen occupations with ≥2000 employees had an increased risk, with health care assistants experiencing the highest risk, and physiotherapists, midwives, dentists and dental assistants as notable exceptions .In social care, four out of fourteen occupations had increased risk, the highest IRR being in nurses. Nursing aides  and teachers/day care assistants for children aged 4–7 also had increased risk, while primary school teachers and social work and counselling professionals had not.Among five jobs in the transportation sector, increased risk was seen among bus and possibly taxi drivers but not lorry and locomotive engine drivers.Computation of IRR by 4-digit DISCO-08 occupations across all industrial sectors independently of COVID-19 JEM assessments revealed few additional occupations with elevated risk not captured by the industrial sector stratified analysis. These include construction managers, medical imaging and equipment operators, chefs, early childhood educators and food and related products machine operators .Strong and robust sex- and age-adjusted associations were seen between COVID-19 related hospital admission and most covariates other than body mass index and positive PCR swab test of one or more family members in the previous 2–3 weeks (supplementary table S3)In this nationwide registry-based follow-up study of COVID-19 related hospital admission during the first two years of the pandemic in Denmark, we observed increased risk in most occupations within healthcare, in several occupations within social care, and in a few occupations within transportation and various other occupations. Adjusted IRR in these at-risk occupations were generally in the range of 1.5–3. No increased risk was seen in the educational and retail sales sectors or in a number of service professions. Our analysis had the strength of being based on a large national cohort, but several potential sources of bias need consideration.Hospital admission is not a perfect proxy for incidence of COVID-19. Admission rates among infected individuals are higher among those who are older, male, of non-white ethnicity, with various comorbidities, and have an unhealthy lifestyle , 40. To A large number of comparisons inevitably produces chance associations, and real associations cannot be distinguished from spurious associations on statistical grounds. The main approach taken to address the multi-comparison problem was to focus on occupations that according to independent expert ratings a priori were more likely to confer increased risk of viral infection. Nevertheless, it should be acknowledged that demonstration of increased (or reduced) risk in some occupations could be the result of random variation regardless of statistical significance. Cautious interpretation and critical assessment of plausibility are needed before specific results are communicated or actions taken based upon findings related to specific occupations. The detail provided by stratification of jobs by industrial sector may be helpful in risk assessment because we expect that the same jobs in different sectors will in some cases have different risks. On the other hand, real risks in some occupations may have been missed because of small numbers. It was, for example, unexpected that the risk in midwives was not elevated, although an explanation might be that both pregnant women and midwives have been unusually careful to avoid infection.Positive PCR swab tests among family members were only weak predictors of COVID-19 related hospital admission 2–3 weeks later despite an extremely high testing activity, particularly during the second year of the epidemic. This finding cannot be taken as strong evidence that viral transmission in the family is of minor importance. Since positive PCR tests are strongly clustered in families in time – many performed within hours the very same day – the sequence of positive testing in a family may not be a reliable indicator of the sequence of infection. Moreover, in spite of high test-activity, there may still be many undetected subclinical cases.The follow-up period included the first two epidemic waves and the initial part of the third wave. The end of follow-up coincided with a time when the less virulent omicron virus variant outnumbered the more lethal alpha, beta, and delta variants. However, there is no reason to expect that this change will have affected occupations differentially, and therefore it should not have been a source of bias.When comparing results across studies undertaken in different places and over different time periods, there is a possibility that differences in risk estimates could reflect not only the effects of bias and chance, but also variation in the extent of societal lockdown and effectiveness of precautionary measures as implemented in different countries at different stages of the pandemic. Results reported here may not apply to other countries or other time periods. Nevertheless, our findings are broadly consistent with those from elsewhere. They corroborate several earlier reports of increased risk among healthcare workers , 23–27, To the extent that the observed risk estimates reflect viral transmission related to working in a particular occupation, our data indicate that in the population and time period studied, recommendations and precautions to mitigate risk were insufficient and need to be revisited by employers and the Labour Inspection Agencies. When working at home is infeasible during periods with high community prevalence of infection, there is a need to develop and implement job- and task-specific guidelines based on the well-established general recommendations. At the same time, the demonstration of increased risk of infection in certain occupations may suggest interventions to protect the public more widely. For instance, elevation of risk among hairdressers might imply an increased risk for customers and family members too. As yet, however, there is little direct evidence of onward household transmission from people working in high-risk occupations , 42.In most occupations where no or only marginally elevated risks (IRR <1.1) were observed, it seems likely either that viral transmission was not occurring in the workplace or that precautions were sufficient to mitigate it – as for instance in the travel, hotel and restaurant businesses, which have been locked down for long periods during the pandemic.Significantly low risk estimates may have occurred in some jobs because limited contact with other people at work meant that SARS-CoV-2 transmission was lower than during leisure-time activities. Alternatively, they could be a consequence of random sampling variation in a context of multiple testing, or the reference groups used may not adequately have represented the lowest occupational exposure levels. The COVID-19 JEM was based upon subjective expert ratings and has so far not been validated .The excessive societal impact of the COVID-19 pandemic may have consequences for occupational health reaching beyond the pandemic itself. In general, transmission of infectious diseases in the workplace has not been given high priority either in research agendas or in occupational health prevention programs , 44. ThiOur study provides strong evidence that the workplace has been an important setting for viral transmission during the SARS-CoV-2 pandemic in Denmark, and that lock-down and other measures to reduce such transmission have not been fully effective. Ways should be sought to reduce risk further, especially in health and social care, and among bus and taxi drivers. In addition, there is mounting evidence to support compensation for COVID-19 as an occupational disease in a number of jobs.


Despite significant improvements in both treatment and prevention strategies, as well as multiple commissioned reviews, there remains uncertainty regarding the survival benefit of repurposed drugs such as colchicine in patients with Coronavirus Disease 2019 (COVID-19) clinical syndrome.In this umbrella review, we carried out a comprehensive search of PubMed, EMBASE, Cochrane Database of Systematic Reviews, Science Citation Index, and the Database of Abstracts of Reviews of Effectiveness between January 1, 2020 and January 31, 2023 for systematic reviews and meta-analyses evaluating the mortality-reducing benefits of colchicine in patients with COVID-19. This was to ascertain the exact relationship between colchicine exposure and mortality outcomes in these cohorts of patients. We utilized A Measurement Tool to Assess systematic Reviews-2 (AMSTAR-2) to conduct an exhaustive methodological quality and risk of bias assessment of the included reviews.We included eighteen meta-analyses  in this umbrella review. Colchicine exposure was associated with an overall reduction of about 32% in the risk of mortality . Further examination of pooled estimates of mortality outcomes by the quality effects model  reported similar point estimates .In a pooled umbrella evaluation of published meta-analyses of COVID-19 patient cohorts, exposure to colchicine was associated with a reduction in overall mortality. Although it remains uncertain if this effect could potentially be attenuated or augmented by COVID-19 vaccination. The exact reason for these discordant outcomes remains unknown. Several factors have been suggested to account for this, including differences in the design of the constituent studies included in the secondary meta-analytical syntheses; differences in constituent patients’ populations; and lately COVID-19 vaccination status of patients included the reviewed studies. Whatever may be the exact reason for the discrepancy in these reported mortality outcomes, there is a residual need to explore further analytical pathways with the view to establishing the exact relationship between colchicine exposure and mortality outcomes in these cohorts. The recent flare of COVID-19 transmission in China and its resultant morbidity toll on the population sends a clear unequivocal reminder that there continue to be residual challenges with this virus both in terms of therapeutics and prevention. Therefore, to conclusively establish the exact relationship between colchicine exposure and mortality, we carried out comprehensive umbrella meta-analyses of published reviews since the onset of the pandemic.Coronavirus Disease 2019 (COVID-19) is a clinical syndromic illness caused by the SARS-COV-2 virus ,4. Howev2CRD42023397246).In conducting this review, we adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) procedure  for the 2.1We searched PubMed, EMBASE, Cochrane Database of Systematic Reviews, Science Citation Index, and database of abstracts of reviews of effectiveness between January 1, 2020 and January 31, 2023 for publications that satisfied prespecified inclusion criteria outlined in the review protocol. We used the following medical subject headings (MESH) terms to identify titles and abstracts for screening: (((colchicine) AND (COVID-19)) OR (Coronavirus 2 disease)) AND . We only included studies with meta-analytical designs exploring the efficacy and safety of colchicine in patients with COVID-19 infection.2.2Following the initial literature search and removal of duplicate publications, we carried out a study eligibility assessment from the resulting abstracts. Two independent reviewers (RS and MA) assessed each study for inclusion in the review based on pre-specified inclusion criteria. In the unlikely event of disagreement between reviewers, this was usually resolved through consensus. Where consensus could not be reached, a third reviewer (MID) was called in to adjudicate. We drew up a final list of all included studies that met the following eligibility criteria: studies published in the English language between January 1, 2020, and January 31, 2023; patients over 18 years of age with COVID-19 infection; exposure to colchicine as part of study participant treatment regimen; reviews providing pooled estimates of mortality following colchicine exposure. We excluded all studies that failed to meet the inclusion criteria.2.3We extracted the following variables from each included study: last name of the first author and the year of publication; study centre/location; the number of COVID-19 patients; odds ratio of mortality outcomes reported by the meta-analysis and the model (random or fixed effects) under consideration. Where alternative effect sizes were given (such as risk ratios or relative risks), these were converted to odds ratios before pooled analyses.We conducted a quality and risk of bias assessment using A Measurement Tool to Assess Systematic Reviews-2 (AMSTAR-2) tool . An exha2.4I2 statistics. We will assume the I2 thresholds of 25%, 50%, and 75% to represent low, moderate, and high between-study variances, respectively. Results were presented as forest plots with odds ratio (OR) estimates for each of the included reviews and overall final pooled OR. We visualized small study effect and publication bias with a funnel and Doi plots and inference was made using Egger's tests. All analyses were conducted with MetaXL, version 5 Descriptive statistics such as median and interquartile range were estimated for age and sample size, whilst categorical data was reported as their respective frequencies and percentages. For studies included in the umbrella review, before we quantify the pooled estimates, we initially converted all reported effect sizes to odd ratios . We then computed the pooled estimates of mortality from the included meta-analyses. We subsequently carried out umbrella meta-analyses using the fixed, random (DerSimonian-Laird), and quality effect models to ascertain the exact point estimate of mortality in COVID-19 patients exposed to colchicine. The quality effects (QE) model reduces estimator variances by redistribution of study weights through prior rescaling of quality ranks (from 0 to 1). We assessed heterogeneity between studies with 33.1n = 194410.0 participants) , we retrieved 106 studies with no duplicates. Following full-text screening, 16 articles . Further examination of pooled estimates of mortality outcomes by the quality effects model  reported estimates within the same ballpark  I2 = 34%, P = 0.34). Vrachatis et al. review is the first investigation of the pooled estimate of colchicine mortality benefit in patients with COVID-19 in January 2021  index 6.28). This is probably due to the heterogeneity of the patient population and differences in the design of studies included in the meta-analyses reviewed by this umbrella review. See We found significant heterogeneity amongst the studies included in this umbrella review  ,43. The 4I2 of 94%). With the successful identification and confirmation of the mortality-reducing properties of COVID-19 vaccination (amongst other measures), the standard of acceptability of new and repurposed drugs in the therapeutics of COVID-19 clinical syndrome has changed vis-à-vis5The result of this umbrella review read together with recent RCTs exploring outcomes in COVID-19 patients [such as Perricone et al. ] will su5.1This umbrella review represents the first and only comprehensive examination of published meta-analyses exploring mortality outcomes in patients with COVID-19, and thus has the potential to inform practice going forward. The relative spread of the constituent reviews throughout the critical years of the pandemic (July 2020 to December 2022) meant that the studies it examined represents the “core” of COVID-19 morbidities and the uncertainty surrounding how best to manage them.This review is limited by confounding factors native to the constituent meta-analyses and the primary studies they reviewed. Additionally, consistent with known flaws of our study design, the validity of umbrella reviews such as ours is pretty much “held hostage” by the methodological quality of the constituent meta-analyses we reviewed. Our determination of pooled estimates of odd ratios using the quality effects model was aimed at mitigating some of these biases. Furthermore, the fact that the population reviewed by this umbrella synthesis was unvaccinated against COVID-19, suggests caution in the generalizability of our findings to the larger COVID-19 population.6In a pooled umbrella evaluation of published meta-analyses of COVID-19 patient cohorts, exposure to colchicine was associated with a reduction in overall mortality. Although it remains uncertain if this effect could potentially be attenuated or augmented by COVID-19 vaccination.This review has no funding affiliation to declare. Open Access funding provided by the Qatar National LibraryNot applicable.Data generated and utilized for analyses of results presented in this manuscript are available from the corresponding author on reasonable requests.All authors listed have significantly contributed to the development and the writing of this article.Data will be made available on request.No additional information is available for this paper.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


In the case of HER2-mutant lung cancers, there are limited approved agents, and the treatment represents a critical unmet medical need because of the poorer survival outcomes compared to patients with additional oncogenic drivers. The recent standard of care of treatment is chemotherapy, but reports suggest that compared with cytotoxic chemotherapy, patients receiving HER2-directed therapies have relatively longer median survival duration. Here, we report a case of HER2 exon 20-mutated metastatic lung adenocarcinoma patient who received trastuzumab emtansine in the third-line setting and achieved durable disease control.Lung cancer is the foremost reason for cancer-related mortality among men and women. The ultimate goal of patient supervision post-diagnosis for advanced cases is to improve survival and quality of life with minimal treatment-associated side effects. With advancements in genomic medicine and a better understanding of cell signaling pathways, many actionable gene mutations have been identified in lung carcinoma, which drastically improve survival outcomes. Mutations in  Lung cancer is the foremost reason for cancer-related mortality among men and women. The ultimate goal of patient supervision after the diagnosis for advanced cases is to improve survival and quality of life with minimal treatment-associated side effects. Enhanced research on the molecular pathways driving cancer in non-small-cell lung cancer (NSCLC) steered advances in targeted therapy with molecular pathway-specific agents in cancer cells -3.MET, AKT, BRAF, PIK3CA, RET, KRAS, and ROS rearrangements . This indicates that HER2 overexpression might have a negative influence on HER2 mutations in terms of response toward T-DM1 . The discrepancy among the data can be partly justified by the smaller sample size of the majority of studies as well as the study designs, i.e., single arm and single center. Overall, it remains a gray area regarding the concomitance of different HER2 alterations and their overall effects on the efficacy of T-DM1 .HER2 is found to be an effective targetable driver mutation. We recommend testing HER2 along with the testing of other rare, potentially targetable genetic alterations for patients whose tumors are observed to be negative for EGFR, ALK, and ROS1. Presently available advanced HER2-targeted agents might provide an added opportunity for the treatment of such patients.In lung cancer, HER2-mutated NSCLC patients according to the latest NCCN guidelines. This report provides evidence of a durable response of approximately six months with this drug in the third-line setting. This report justifies the need for further studies to evaluate response to T-DM1, especially in HER2-mutated lung carcinoma patients progressing on routine chemotherapy.T-DM1 is now approved as a treatment of choice for


A public health crisis has been threatening the world since the new 2019 coronavirus (2019-nCoV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged and began to spread in late 2019. As of April 10, 2022, more than 496 million confirmed cases and more than 6 million deaths had been reported in the six WHO regions. However, the total impact of the pandemic has been far greater than reported deaths indicate. Although reported deaths from COVID-19 between January 1, 2020, and December 31, 2021, were 5.94 million worldwide, a recent work estimates that 18.2 million people actually died worldwide due to the COVID-19 pandemic  [Vaccines have significantly reduced COVID-19-related deaths, with more than 10 billion doses having been administered worldwide. However, the distribution of vaccines remains highly unequal. Most of the world’s wealthier countries have vaccinated and even administered booster doses to most of their populations, yet the poorest countries have extremely low vaccination coverage rates. In recent months, we have witnessed a turning point in the pandemic due to the high contagiousness of the new variants, their lower aggressiveness and the fact that a large part of the population is immunized through vaccines or through natural infection. Due to these facts, many local governments have relaxed public health restriction measures. Nevertheless, experience and data suggest that new variants will emerge that will generate new outbreaks and have unpredictable implications for prevention and treatment strategies.The rapid and accurate diagnosis of SARS-CoV-2 infection has become a priority issue since first cases were reported. Different methods have been developed, with several strengths and limitations depending on the target population, the epidemiological scenario, and the turn-around time. Real-time polymerase chain reaction (RT-PCR) identifies the presence of SARS-CoV-2 RNA in biological samples. It is considered the gold standard diagnostic test due to their high specificity and sensitivity. RT-PCR is based on the specific detection of different regions of the virus genome, mainly structural protein genes, such as spike, envelope, membrane, and nucleocapsid, preferably with simultaneously detection of several viral targets to avoid false-negative results. Although RT-PCR is the gold standard, the need for trained personnel and specific equipment, the cost of technique and the long turn-around time has led to the development of other techniques available to meet the high demand for diagnosis necessary in a pandemic status [Antigen tests (AgT) are immunoassays that detect the presence of a specific viral antigen. These tests can be performed quickly and at the same point of care, with turn-around times less than 30 min and low costs associated. AgT are in general less sensitive than molecular techniques, so these tests are recommended during the first days of symptoms , to detect individuals with greater viral load (greater risk of contagion) and in the study of outbreaks in closed environments. While molecular techniques can be excessively sensitive and remain positive for a long-time detecting individual who are no longer contagious, AgT more accurately reflect the patient’s infective capacity so they are widely recommended in the last stage of the infection to end the quarantine of positive cases detected. Furthermore, these tests can only be performed on nasopharyngeal swabs and, as they are qualitative, cannot quantify the amount of antigen present . Unlike Finally, it is described the continuous appearance of new viral variants because of numerous gene mutations from the original Wuhan-strain. The CDC and the WHO have classified some of these new strains as variants of concern (VOC). These mutations may affect important viral functional characteristics, including infectivity and an enhanced ability to evade natural infection and/or vaccine-induced neutralizing antibody responses. Therefore, it is a matter of concern since these new variants could evade immune responses from previous vaccination and or infection, or even select drug-resistant mutants. Although next-generation sequencing (NGS) is considered the gold standard for SARS-CoV-2 variant identification and characterization of mutations in the viral genome, it is a complex technique, only available to the most specialized laboratories. Multiple commercial easy RT-PCR kits have been developed for the study of these new variants, allowing faster and more representative typing of circulating strains. NGS allows confirm RT-PCR results and monitor the emergence and dynamics of novel SARS-CoV-2 variants. Considering the dynamics of viral mutation and the speed with which new VOC emerge, continuous surveillance of variants is mandatory .On the other hand, the detection of antibodies against SARS-CoV-2 allows the identification of specific markers associated with vaccine response (anti-spike antibodies), since most vaccines are based on the Spike protein. To differentiate the population that has undergone a natural infection, anti-nucleoprotein antibodies (anti-N) can also be detected in serum. The quantification of anti-spike allows assessing the degree of response to vaccination and can confirm an infection; if an increase is detected without vaccine boosting and/or anti-N seroconversion is observed. Similarly, reinfection can be confirmed by evaluating increases in antibody levels against these two targets. A WHO international standard (NIBSC code 20/136) has been developed whose values are expressed as binding antibody units (BAU) per mL. The level of 143 BAU/mL of antibodies has been proposed as an adequate level of protection against infection , but thiThe presence of neutralizing antibodies is related to protection against SARS-CoV-2 virus infection. However, the circulation of VOCs such as Omicron BA.1 or BA.2, with a high rate of mutations in the Spike protein, reduces the protective capacity of these antibodies generated by the vaccine or by previous infections . In addiBoth vaccines and natural infection by SARS-CoV-2 or similar coronaviruses, induce the generation of specific T cells with effector capacity and immunological memory. The action of T cells is essential to reduce the severity of the infection and facilitate the recovery of the infected individual. In addition, its protective effect can last for years and does not depend on the infecting VOC, as there is a cross-protective effect induced by different coronaviruses .The evaluation of specific T cells is more expensive, labor intensive and time consuming than serology, since it requires the stimulation of viable cells with specific SARS-CoV-2 antigens, and the subsequent measurement of cytokines produced . The reference method requires the separation of PBMC cells by Ficoll gradient and study by flow cytometry. However, other tests have been developed using whole blood, suitable for their use in the clinical lab and giving valid results to evaluate the specific cellular response . These mThe different methods available allow the detection of specific T cells, which eventually reduce the chance of serious illness. In addition, T-cell activity is preserved longer than antibodies after an infection or vaccination. Even, the Omicron can be target of T cells generated by different vaccines or unvaccinated convalescent COVID-19 patients. It has been recently reported that they maintained 70–80% of the CD4+ and CD8+ response to Omicron spike and the magnitude of cross-reactive T cells was similar for Omicron, Beta, and Delta variants as T cells can recognize more sites along the spike protein than can antibodies .To summarize, unless vaccines are reformulated to improve the production of specific antibodies against new variants, those individuals with specific T cells following vaccination or natural infection will get little benefit from booster shots. Therefore, the assessment of T-cell activity may be a suitable tool to personalize the need for further boosting, particularly among vulnerable populations who may be at increased risk of severe disease.


Over the next decade, millions of deaths could be prevented by increasing access to vaccines in low-income and middle-income countries (LMICs). The COVID-19 pandemic has demonstrated that the research and development (R&D), launch and scale up timelines of vaccines can be drastically shortened. This study compares such timelines for eighteen vaccines and identifies lessons and implications for accelerating the R&D, launch and scale up process for other vaccine candidates. To replicate the rapid R&D process of the COVID-19 vaccines, future vaccine R&D should capitalise on public–private knowledge sharing partnerships to promote technology innovation, establish regional clinical trial centres and data sharing networks to optimise clinical trial efficiency, and create a funding mechanism to support research into novel vaccine platforms that may prove valuable to quickly developing vaccine candidates in future global health emergencies. To accelerate the launch timeline, future efforts to bring safe and efficacious vaccines to market should include LMICs in the decision-making processes of global procurement and delivery alliances to optimise launch in these countries, strengthen the WHO prequalification and Emergency Use Listing programs to ensure LMICs have a robust and transparent regulatory system to rely on, and invest in LMIC regulatory and manufacturing capacity to ensure these countries are vaccine self-sufficient. Lastly, efforts to accelerate scale up of vaccines should include the creation of regional pooled procurement mechanisms between LMICs to increase purchasing power among these countries and an open line of clear communication with the public regarding pertinent vaccine information to combat misinformation and vaccine hesitancy. The end-to-end scale up timeline varied substantially among different vaccines. However, the COVID-19 pandemic has demonstrated that the research and development (R&D), launch and scale up timelines of vaccines can be drastically shortened and lessons can be applied to other vaccines.Funding the development of novel vaccine platforms, establishing regional clinical trial centres and data sharing networks, and forming public–private knowledge sharing partnerships are all strategies that may accelerate the R&D of new and existing vaccine candidates.Including low-income and middle-income countries (LMICs) in the decision-making processes of global procurement and delivery alliances, strengthening the WHO prequalification and Emergency Use Listing programmes, and investing in LMIC regulatory and manufacturing capacity will likely bring LMICs closer to a state of vaccine self-sufficiency thereby reducing delays to launching new and existing vaccines in these countries.Creating regional pooled procurement mechanisms between LMICs, including LMICs in global supply chain decision-making, and keeping an open line of clear communication with the public regarding pertinent vaccine information may increase uptake of new and existing vaccines in LMICs and other countries worldwide.The COVID-19 pandemic revealed that vaccine development, launch and scale up timelines can be shortened drastically. Some studies have identified key factors that facilitated the early development of COVID-19 vaccines.Vaccination remains one of the most cost-effective public health interventions available to us today.Current efforts to develop and scale up vaccines to countries with the greatest need are slow. Recent projections show that only 5 of 195 countries measured are on track to attain Sustainable Development Goal 3 which calls for 100% coverage of seven common vaccines  among all at-risk populations by 2030.15There is no standardised end-to-end scale up pathway for vaccines and many factors could affect the development, launch and scale of vaccines. To start with, VPDs are more prevalent in LMICs and there is a lack of economic incentives for developers to invest in R&D for those vaccines.et al’s list of Gavi supported vaccinesWe compared the end-to-end scale up pathway of 10 COVID-19 vaccines and 8 non-COVID-19 vaccines. We defined the end-to-end pathway into three milestones covering R&D, launch and scale.Among COVID-19 vaccines the median time taken was 0.90 years (max: 1.68 years) for R&D, 0.05 years (max: 0.31 years) for launch and 0.92 years (max: 0.97 years) for scale. Among non-COVID-19 vaccines the median time taken was 14.16 years (max: 34.02 years) for R&D, 0.62 years (max: 1.33 years) for launch, and 7.53 years for scale (max: 18.01 years). Only two vaccines reached at least 20% target population in LMICs within 1 year after their launch. Noticeably, we also observed that the durations of different milestones varied substantially among non-COVID-19 vaccines.The time taken for R&D of the COVID-19 vaccines is nearly 16 times shorter than that of the non-COVID-19 vaccines included . The red10.1136/bmjgh-2023-012855.supp1Supplementary dataClinical trial and regulatory efficiencies have also contributed to the quick development of COVID-19 vaccines. Several innovative strategies have been used to reduce the time needed for COVID-19 vaccine candidates to demonstrate efficacy and safety and obtain regulatory approval including: (1) rapid identification of clinical trial sites based on the monitoring of COVID-19 infection rates across the world; (2) adaptive clinical trial designs whereby key phases of the trial process are conducted in parallel rather than sequentially; (3) harmonised clinical trial protocols in which similar vaccine candidates from different developers use the same protocol and (4) rolling regulatory reviews that allow developers to submit (and regulators to review) clinical trial data on a continuous rather than intermittent basis.Partnerships also played an important role in reducing the time needed to develop COVID-19 vaccines. By mid 2021, at least 81 partnerships, targeted at developing a COVID-19 vaccine, had been registered by the WHO about half of which were material transfer partnerships and half knowledge sharing partnerships.The launches of COVID-19 vaccines took about 12 times shorter than that of non-COVID-19 vaccines . The WHO18Although the WHO prequalification/EUL programmes helped LMICs receive COVID-19 vaccine doses quickly, the COVID-19 pandemic highlighted the value of LMICs increasing their regulatory capacities. The WHO Global Benchmarking Tool allows national regulatory authorities to assess their level of ‘maturity’ through a comprehensive set of indicators.Public–private partnerships were crucial to quickly launching COVID-19 vaccines in LMICs.COVID-19 vaccines were over eight times faster to reach 20% uptake across LMICs than that of other vaccines . While i44Despite the efforts in scaling up of COVID-19 vaccines in LMICs, the pandemic revealed inefficiencies in vaccine manufacture, distribution, delivery and demand generation. According to a WHO survey of influenza manufacturers in 2019, the global vaccine manufacture capacity could only vaccinate 25% of the world’s population in the first year.Valuable insights regarding the inclusion of LMIC stakeholders at the decision-making table of vaccine procurement and delivery logistics may be drawn from the scale up of nOPV2. nOPV2 received EUL status by the WHO in 2020.Lastly, it is important to note that the rapid development of COVID-19 vaccines has given rise to vaccine hesitancy across the world.Based on the public health impact of infectious diseases, insights gained and lessons learnt from the rapid R&D, launch and scale up of COVID-19 vaccines might have different implications for the vaccines targeting other infectious diseases. Funding the development of novel vaccine platforms, establishing regional clinical trial centres and data sharing networks, and forming public–private knowledge sharing partnerships are all strategies that may accelerate the R&D of new and existing vaccine candidates. In addition, including LMICs in the decision-making processes of global procurement and delivery alliances, strengthening the WHO prequalification and EUL programmes, and investing in LMIC regulatory and manufacturing capacity will likely bring LMICs closer to a state of vaccine self-sufficiency thereby reducing delays to launching new and existing vaccines in these countries. Lastly, creating regional pooled procurement mechanisms between LMICs, including LMICs in global supply chain decision-making, and keeping an open line of clear communication with the public regarding pertinent vaccine information may increase uptake of new and existing vaccines in LMICs and other countries worldwide.


BackgroundCervical cancer is the second deadliest for women between the ages of 20 and 39 years. Even with prevention tactics for screening, incident rates and mortality of cervical cancer remain high. Olive has been shown to have many beneficial effects in humans concerning cardiovascular disease and inflammation. Despite these promising benefits, little is known about its effect on cervical cancer. This study examined the effects and mechanism of effects of olive extract (OE) on the HeLa cervical cancer cell line.MethodologyWe utilized clonogenic survival assay, quick cell proliferation assay, and caspase-3 activity to investigate the effect of OE on the proliferation and apoptosis of the cervical cancer cell line HeLa. To investigate the mechanisms behind these findings, Reverse transcription polymerase chain reaction and immunohistochemistry were performed.ResultsOE inhibited the growth and proliferation of HeLa cells. In comparison to the control, the percentage of colonies, as well as the optical density of the cervical cancer cells, was found to be decreased. In addition, the relative activity of caspase-3, a marker for apoptosis, was increased after treatment with OE. The anti-proliferative effect of OE on HeLa cells correlated with the increase of an anti-proliferative molecule p21. However, the pro-apoptotic effect of OE was not correlated with the change in major pro-apoptotic or anti-apoptotic molecules examined in this study.ConclusionsOur study suggests that OE inhibits the growth of HeLa cervical cancer cells by upregulation of p21. Further investigation of the effects of OE on cervical cancer and other cancers is warranted by these results. Cancer is the second leading cause of death worldwide, just behind cardiovascular disease, and cervical cancer has the fourth highest incidence rate in women . AlthougOne of the many components of naturally occurring olive extract (OE) is phenolic compounds, which have been shown to potentially improve cardiovascular health, contain anti-inflammatory properties, provide neuroprotection, and possess antimicrobial activity -9. OtherThis article was previously posted to the ResearchSquare preprint server on October 19th, 2022.Tumor cell line2 incubator . Once the HeLa cell cultures reached 70% confluence, they were subjected to designed experimental treatment regimens.The American Type Culture Collection  was the source of HeLa cells, the cervical cancer cell line. Dulbecco’s modified eagle medium with 10% heat-inactivated fetal bovine serum and 1% penicillin-streptomycin was used to maintain the cells and was provided by Invitrogen . The cultures were kept at 37°C in a humidified 5% COTreatment with OEThe concentration of OE and the duration of treatment were determined by our previous experiments . We treaClonogenic survival assayThe treatment was followed by a clonogenic survival assay; it was performed as outlined in previous experiments . ResultsQuick cell proliferation assay for measurement of HeLa cell proliferationThe activity of mitochondrial dehydrogenase directly correlates with the proliferation of viable cells; this produces formazan dye which was quantified by spectrophotometer. A quick cell proliferation assay kit from BioVision was employed, and a procedure that was detailed in our previous studies was followed closely .Immunohistochemistry (IHC)IHC staining p21 was done using a protocol described previously . The dilReverse transcriptase-polymerase chain reaction (RT-PCR)First, both the OE-treated and control HeLa cells were washed with phosphate-buffered saline and then homogenized in TRIzol (Invitrogen). Subsequently, 1 μg RNA was reverse transcribed post-extraction as previously documented . ConcentMeasurement of caspase-3 activityThe activity of caspase-3 was followed as a marker of pro-apoptotic activity. A BioVision caspase-3/CPP32 colorimetric assay kit was utilized to measure the caspase-3 activity in HeLa cells following a procedure documented previously .Statistical analysisStatistical data analysis was performed using an unpaired, two-tailed t-test, with a p-value <0.05 considered statistically significant. Each experiment was performed three times to ensure precision and limit significant errors.Effect of OE on HeLa cell survivalHeLa cells were treated for 72 hours with OE or medium alone (control) at 70% confluence to evaluate cell survival in the presence of OE. The clonogenic survival assay showed a significant decrease in the percentage of cell colonies of HeLa cells treated with OE versus the control group  and anti-proliferative  molecules was measured. This measurement was performed using RT-PCR in OE-treated versus control groups  and anti-apoptotic  molecules were measured Figure . HoweverThis study investigated the potential role of OE, a naturally occurring substance, on HeLa cervical cancer cell growth. It is well known that the balance, or lack thereof, between cell proliferation and cell apoptosis is tightly regulated through various molecules that govern these processes. The results of this study uncovered that OE inhibits the proliferation of HeLa cells, mainly by upregulating the anti-proliferative molecule p21. Currently, very little is known about the effects of OE on cervical cancer. To our knowledge, this is only the second study to explore the effects and mechanism of OE on HeLa cell growth in vitro .The primary known cause of cervical cancer is HPV; two HPV types 16 and 18) account for about 70% of all cervical cancer, and the possible mechanism by which HPV does so has been well studied and identified . One of  and 18 aContrary to the observed effect of OE on HeLa cell growth, a significant decrease in the expression of the anti-proliferative molecule p27 was found in the treatment group. This paradoxical phenomenon has similarly been discovered in previous studies from our lab -28. AnotFurthermore, the results of the caspase-3 activity analysis indicate that HeLa cells in the OE treatment group underwent significantly more apoptosis compared to the control group. As a result, the expression of multiple pro- and anti-apoptotic molecules was determined. No statistically significant difference in the expression of these molecules was found between the OE treatment group and the control group. These results indicate a need for future research into more apoptotic regulatory molecules to help uncover the possible mechanism at play. There is some evidence that p21 is involved in the induction of apoptosis, but that a sole increase in cellular p21 is not capable of inducing apoptosis . OverallAlthough limited, previous literature on this topic reveals similar findings to those uncovered by this experiment. A prior study on the effect of olive leaf extract and HeLa cells reported an upregulation of p21 paired with a downregulation of cyclin D1, leading to reduced proliferation and increased apoptosis of HeLa cells . Our stuThe findings of this experiment are promising; however, we understand that this is only an in vitro study and that there are significant limitations to making conclusions based off of this research. First, only one cervical cancer cell line (HeLa) was used. We look to evaluate the effects of OE on other cervical cancer cell lines and other cancer lines in future studies to reach a better understanding of these effects. Second, our proposed mechanism does not provide information for the pro-apoptotic effect observed and differs slightly from an earlier study on this topic, as mentioned previously. Third, our mRNA expression results do not provide context into the exact mechanism of how OE inhibits the growth of HeLa cells, given that p53 expression was not significantly altered versus the control group. This effect may be due to a p21-independent mechanism, but more research is needed to make a definitive conclusion. This does warrant evaluation of other molecules involved in p21-dependent cell cycle regulatory pathways.The leading cause of cervical cancer, HPV, causes tumor cell proliferation by decreasing the anti-proliferative effect of p21. In this study, we conclude that OE inhibited the growth of HeLa cells through the upregulation of p21. Although there are high-quality screening methods and available vaccines against HPV, cervical cancer is still the second leading cause of cancer death in middle-aged women (20-39 years old), especially those of lower socioeconomic status. Thus, any improvement in cervical cancer treatment could prevent many unfortunate and unnecessary deaths. Future research should evaluate the effects of OE, a naturally occurring substance, on other cervical cancer cell lines and explore other molecules involved in p21-dependent cell cycle regulatory pathways. Overall, this study provides a foundation for future research into the anti-proliferative effects of OE and its potential use in cancer treatment.