Objectives: The 20-valent pneumococcal conjugate vaccine (PCV20) has been introduced in Israel. Its public health benefit depends on its effect on mortality caused by PCV20 serotypes not present in 13valent pneumococcal conjugate vaccine (PCV13) (PCV20non13). We aimed to describe invasive pneumococcal disease (IPD) characteristics and case-fatality rate (CFR) among adults by serotypes. Methods: We analysed data from the Israeli nationwide surveillance database of IPD in adults, 2009-2018. The primary outcome was in-hospital CFR within 30 days, focusing on specific serotypes. Adjusted ORs (aORs) for association between PCV20non13 serotypes and mortality were calculated using logistic regression. Results: Overall, 3864 IPD episodes were reported, 3733 (96.6%) with known serotype, 54% (1705/3123) were in men; 54% (1997/3733) were aged >= 65 years. PCV13-IPD cases constituted 40% of all IPD and decreased during the study years. PCV20non13 and nonPCV20 serotypes constituted 26% and 34% of cases, respectively, and increased over time. The most frequent non-PCV13 serotypes detected were PCV20non13 serotypes 8 (8%), 12F (7.2%), 22F (3%), and nonPCV20 serotype 16F (5%). In-hospital CFR was 22% (698/3140). CFR for PCV13 serotype was 21.1% (265/1255); for PCV20non13, it was 16.2% (124/766); and for nonPCV20, it was 28.5% (289/1014). Among PCV20non13 serotypes compared with PCV13 serotypes, 11A was associated with higher CFR (41%, aOR 3.1, 95% CI: 1.64-5.83), whereas serotype 8 was associated with lower CFR (8%, aOR: 0.5, 95% CI: 0.3-0.8). Discussion: PCV20non13 serotypes constituted 26% of all adult IPD in the post-PCV13 era. CFR from PCV20non13 serotype IPD was comparable with that from PCV13 serotypes. These data support the potential added benefit of PCV20 in reducing mortality from IPD, though mortality remains substantial from nonPCV20 serotypes. Future IPD-related mortality will depend on the evolution of serotype distribution over time. Anat Wieder-Finesod, Clin Microbiol Infect 2025;31:226 (c) 2024 Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases.

Understanding how interpersonal interactions and immunological factors shape severe acute respiratory syndrome coronavirus 2 transmission in households is crucial for designing control measures. We developed a Bayesian data augmentation transmission model to evaluate the effects of isolation, parental care, and vaccine-induced immunity on Delta variant transmission from the follow-up of 1093 Israeli households (July-August 2021). Among the 2883 household contacts, 1096 (38%) were infected. Children were 38% (95% Credibleconfidence interval [CrI], 7%-81%) more likely to be infected than adults. Isolation measures reduced transmission by 52% (95% CrI, 46%-57%). Transmission was 39% (95% CrI, 11%-76%) higher between children and female adults than between children and male adults. Vaccine effectiveness was 78% (95% CrI, 54%-90%), 85% (95% CrI, 70%-94%), and 73% (95% CrI, 49%-88%), respectively, for 1, 2, and 3 recent vaccine doses (within <= 90 days) but dropped to 18% (95% 95% CrI, -6% to 36%) for 2 doses administered >90 days earlier. Household member interactions significantly shaped transmission, and isolation measures effectively reduced transmission.

Background/Objectives: Millions of individuals worldwide continue to experience symptoms following SARS-CoV-2 infection. This study aimed to assess the prevalence and phenotype of multi-system symptoms attributed to Long COVID—including fatigue, pain, cognitive-emotional disturbances, headache, cardiopulmonary issues, and alterations in taste and smell—that have persisted for at least two years after acute infection, which we define as “persistent Long COVID”. Additionally, the study aimed to identify clinical features and blood biomarkers associated with persistent Long COVID symptoms. Methods: We sent a detailed long COVID symptoms questionnaire to an existing cohort of 1258 vaccinated adults (age 18–79 years) who had mild infection (e.g., non-hospitalized) SARS-CoV-2 Delta variant 2 years earlier. These individuals had comprehensive datasets, including blood samples, available for further analysis. We estimated prevalence of persistent long COVID two years post-infection using weighted adjustment (Horvitz–Thompson estimator) to overcome reporting bias. Multivariable logistic regression models were used to determine association of clinical features and blood biomarkers (pre-infection SARS-CoV-2 RBD-IgG, SARS-CoV-2 neutralizing antibodies, and pre-infection and post-infection neurofilament light) with prevalence of persistent long COVID. Results: N = 323 participants responded to the survey, of whom N = 74 (23%) reported at least one long COVID symptom that had persisted for two years after the acute infection. Weighted prevalence of persistent long COVID symptoms was 21.5% (95% CI = 16.7–26.3%). Female gender, smoking, and severity of acute COVID-19 infection were significantly associated with persistent Long COVID. The blood biomarkers assessed were not significantly associated with persistent Long COVID. Conclusions: Among vaccinated adults two years after mild infection with Delta variant SARS-CoV-2, persistent symptoms attributed to Long COVID are extremely common, certain subgroups are at higher risk, and further research into biological mechanisms and potential treatment targets is needed.

OBJECTIVES:End-of-life (EoL) processes are a complex socio-normative and ethical phenomenon. This study aimed to generate a database of public opinion in Israel concerning EoL processes and decisions and to identify differences in attitudes across subgroups in the population, particularly based on experience as a family caregiver of a dying patient.METHODS:This cross-sectional study was performed in late March 2022. The study utilized an online sample of 605 adults over the age of 50 including those who accompanied a loved one to their death in the last 3 years. Participants were requested to provide their opinions and attitudes on several aspects of EoL decisions, including truth-telling, medically assisted dying, EoL procedures, pre-death actions, and family caregivers' engagement.RESULTS:While only 27% and ∼30% of participants support artificial respiration or feeding (respectively) of terminally ill patients, 66% support analgesic treatment, even at the risk of shortening life. The data show an association between religiosity and agreement with life-extending procedures. For example, while 83% of seculars support medically assisted dying, only 59% and 26% of traditional and religious respondents support it. However, no statistically significant differences were observed in support of family involvement in EoL process in any sociodemographic variable.SIGNIFICANCE OF RESULTS:The results of this study suggest that the Israeli public is relatively polarized on several issues about EoL processes, specifically patient autonomy and medically assisted dying. Yet, at the same time, there is a consensus among the Israeli public about certain EoL elements, particularly the importance of family caregivers in the EoL decision-making process.

Background End-of-life (EoL) care practices (EoLCP) are procedures carried out at the EoL and bear directly on this stage in the patient’s life. Public support of these practices in Israel is far from uniform. Previous studies show that while ∼30% of participants support artificial respiration or feeding of terminally ill patients, 66% support analgesic treatment, even at the risk of shortening life. This study aimed to create a typology of six end-of-life care practices in Israel and assess the association of medical, social, and normative factors with the implementation of those practices. These practices included mechanical ventilation, artificial feeding, deep sedation, providing information to the patient and family caregivers, including family caregivers in EoL decision-making, and opting for death at home. Methods This cross-sectional study was performed as an online survey of 605 adults aged 50 or more in Israel, of which ~ 50% ( n = 297) reported supporting a dying terminally ill relative in the last 3 years. Participants were requested to provide their account of the EoL process of their relative dying from a terminal illness in several aspects, as well as the EoL care practices utilized by them. Results The accounts of the 297 interviewees who supported a dying relative reveal a varied EoL typology. The utilization of end-of-life care practices was associated with the socio-normative beliefs of family caregivers but not with their socioeconomic status. Strong correlations were found between family caregiver support for three key practices (mechanical ventilation, artificial feeding, and family involvement in EoL) and the actual utilization of these practices in the care of dying patients. Conclusions The findings portray an important image of equity in the utilization of EoLCP in Israel, as the use of these practices was not associated with socioeconomic status. At the same time, the study found substantial diversity in family caregivers’ preferences regarding EoL care practices use not related to socioeconomic status. We believe that differences in preferences that do not lead to problems with equity or other important societal values should be respected. Accordingly, policymakers and health system leaders should resist calls for legislation that would impose uniform EoL practices for all Israelis. Instead, they should take concrete steps to preserve and enhance the widespread current practice of practitioners to adapt EoL care to the varied needs and preferences of Israeli families and cultural, social, and religious subgroups. These steps should include providing frameworks and tools for family caregivers to support their loved ones close to their deaths, such as educational programs, seminars, supportive care before and during the end of life of their loved ones, etc.

To study the differences in the immune response to SARS-CoV-2 infection compared to the response to vaccination, we characterized the humoral immune kinetics of these situations. In this prospective longitudinal study, we followed unvaccinated COVID-19-recovered individuals (n = 130) and naïve, two-dose BNT162b2-vaccinated individuals (n = 372) who were age- and BMI-matched for six months during the first pandemic year. Anti-RBD-IgG, neutralizing antibodies (NAbs), and avidity were assessed monthly. For recovered patients, data on symptoms and the severity of the disease were collected. Anti-RBD-IgG and NAbs titers at peak were higher after vaccination vs. after infection, but the decline was steeper (peak log IgG: 3.08 vs. 1.81, peak log NAbs: 5.93 vs. 5.04, slopes: −0.54 vs. −0.26). Peak anti-RBD-IgG and NAbs were higher in recovered individuals with BMI > 30 and in older individuals compared to individuals with BMI < 30, younger population. Of the recovered, 42 (36%) experienced long-COVID symptoms. Avidity was initially higher in vaccinated individuals compared with recovered individuals, though with time, it increased in recovered individuals but not among vaccinated individuals. Here, we show that while the initial antibody titers, neutralization, and avidity are lower in SARS-CoV-2-recovered individuals, they persist for a longer duration. These results suggest differential protection against COVID-19 in recovered-unvaccinated vs. naïve-vaccinated individuals.

Background Identifying COVID-19 correlates of protection and immunity thresholds is important for policy makers and vaccine development. We aimed to identify correlates of protection of BNT162b2 (Pfizer-BioNTech) vaccination against COVID-19.Methods In this prospective cohort study, households within a radius of 40 km of the Sheba Medical Center in Israel in which a new SARS-CoV-2 infection (defined as the index case) was detected within the previous 24 h were approached between July 25 and Nov 15, 2021. We included adults (aged >18 years) who had received one or two vaccine doses, had an initial negative SARS-CoV-2 PCR and no previous infection reported, and had a valid IgG and neutralising antibody result. The exposure of interest was baseline immune status, including IgG antibody concentration, neutralising antibody titre, and T-cell activation. The outcomes of interest were PCR-positive SARS-CoV-2 infection between day 2 and day 21 of follow-up and intensity of disease symptoms (self-reported via a telephone questionnaire) among participants who had a confirmed infection. Multivariable logistic and ordered logit ordinal regressions were used for the adjusted analysis. To identify immunological thresholds for clinical protection, we estimated the conditional probability of infection and moderate or severe disease for individuals with pre-exposure IgG and neutralising antibody concentrations above each value observed in the study data.Findings From 16 675 detected index cases in the study region, 5718 household members agreed to participate, 1461 of whom were eligible to be included in our study. 333 (22.8%) of 1461 household members who were not infected with SARS-CoV-2 at baseline were infected within 21 days of follow-up. The baseline (pre-exposure) IgG and neutralising antibodies were higher in participants who remained uninfected than in those who became infected (geometric mean IgG antibody concentration 168.2 binding antibody units [BAU] per mL [95% CI 158.3-178.7] vs 130.5 BAU/mL [118.3-143.8] and geometric mean neutralising antibody titre 197.5 [181.9-214.4] vs 136 .7 [120.3-155.4]). Increasing IgG and neutralising antibody concentrations were also significantly associated with a reduced probability of increasing disease severity. Odds of infection were significantly reduced each time baseline IgG antibody concentration increased by a factor of ten (odds ratio [OR] 0 center dot 43 [95% CI 0.26-0.70]) and each time baseline neutralising antibody titre increased by a factor of two (0.82 [0.74-0.92]). In our cohort, the probability of infection if IgG antibody concentrations were higher than 500 BAU/mL was 11% and the probability of moderate disease severity was 1%; the probability of infection if neutralising antibody titres were above or equal to 1024 was 8% and the probability of moderate disease severity was 2%. T-cell activation rates were not significantly associated with reduced probability of infection (OR 1.04, 95% CI 0.83-1.30).Interpretation Both IgG and neutralising antibodies are correlates of protection against SARS-CoV-2 infection. Our data suggest that IgG concentrations higher than 500 BAU/mL and neutralising antibody titres of 1024 or more are thresholds for immunological protection from SARS-CoV-2 delta variant infection. Potentially, updated protective thresholds against emerging variants of concern could be calculated, which could support decision makers on administration of new vaccination strategies and on the optimal period between vaccine doses.Funding Israeli Ministry of Health. Copyright (c) 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license.

As the effectiveness of a two-dose messenger RNA (mRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine regimen decreases with time, a third dose has been recommended. Here, we assessed immunogenicity, vaccine effectiveness and safety of the third BNT162b2 vaccine dose in a prospective cohort study of 12,413 healthcare workers (HCWs). Anti-RBD immunoglobulin G (IgG) levels were increased 1.7-fold after a third dose compared with following the second dose. Increased avidity from 61.1% (95% confidence interval (CI), 56.1-66.7) to 96.3% (95% CI, 94.2-98.5) resulted in a 6.1-fold increase in neutralization titer. Peri-infection humoral markers of 13 third-dose Delta variant of concern (VOC) breakthrough cases were lower compared with 52 matched controls. Vaccine effectiveness of the third dose relative to two doses was 85.6% (95% CI, 79.2-90.1). No serious adverse effects were reported. These results suggest that the third dose is superior to the second dose in both quantity and quality of IgG antibodies and safely boosts protection from infection.

OBJECTIVE:To assess the validity of Antigen rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 as decision support tool in various hospital-based clinical settings.DESIGN:Retrospective cohort study among symptomatic and asymptomatic patients and Healthcare workers (HCW).SETTING:A large tertiary teaching medical center serving as a major COVID-19 hospitalizing facility.PARTICIPANTS AND METHODS:Ag-RDTs' performance was assessed in three clinical settings: 1. Symptomatic patients and HCW presenting at the Emergency Departments 2. Asymptomatic patients screened upon hospitalization 3. HCW of all sectors tested at the HCW clinic following exposure.RESULTS:We obtained 5172 samples from 4595 individuals, who had both Ag-RDT and quantitative real-time PCR (qRT-PCR) results available. Of these, 485 samples were positive by qRT-PCR. The positive percent agreement (PPA) of Ag-RDT was greater for lower cycle threshold (Ct) values, reaching 93% in cases where Ct-value was <25 and 85% where Ct-value was <30. PPA was similar between symptomatic and asymptomatic individuals. We observed a significant correlation between Ct-value and time from infection onset (p<0.001).CONCLUSIONS:Ag-RDT are highly sensitive to the infectious stage of COVID-19 manifested by either high viral load (lower Ct) or proximity to infection, whether patient is symptomatic or asymptomatic. Thus, this simple-to-use and inexpensive detection method can be used as a decision support tool in various in-hospital clinical settings, assisting patient flow and maintaining sufficient hospital staffing.

Background: Identifying COVID-19 correlates of protection and immunity thresholds is important for policymakers and vaccine development.Methods: In this prospective cohort study, we examined the association between immune status of household members exposed to an index case and their subsequent risk of infection and disease severity. Multivariable logistic and ordered logit ordinal regressions were used. To identify thresholds, we estimated the conditional probability of infection and moderate/severe disease for individuals with pre-exposure IgG and neutralizing antibody titers above each level observed in the study data.Findings: Overall, 337 of 1532 SARS-CoV-2 negative-at-baseline household members were infected within 21 days of follow-up. The baseline (pre-exposure) IgG and neutralizing antibodies were higher in those who remained uninfected – geometric mean titer of 166.2BAU (95% CI: 155.3-177.9) vs. 124.9BAU (95% CI: 111.2-138.9) and 1:201.5 (95% CI: 184.6-220.0) vs. 1:141.7 (95% CI: 122.5-163.8), respectively. Higher IgG and neutralizing antibody titers were also significantly associated with a reduced probability of increasing levels of disease severity. IgG antibody levels of 500BAU and 300BAU and neutralizing titers above 1:512 were found to provide ≥90% protection from both infection and symptomatic disease, respectively.Interpretation: Both IgG and neutralizing antibodies are correlates of protection. Our data suggest threshold protective levels of IgG>500BAU or neutralizing antibody titers>512 for Delta VOC infection. No significant correlation between T-cell activation and protection from infection, was found.Funding: This study was funded by the Israeli Ministry of HealthDeclaration of Interest: GRY served as a member of an Advisory Board of Moderna, received consulting fees from Medison, speaking fees from Teva, MSD, Pfizer, Astrazeneca and Medison. YL received a grant from Pfizer outside the submitted work. All other authors declare of no CoI.Ethical Approval: The protocol (SMC-8130-21) was approved by the Institutional Review Board of the Sheba Medical Center and written informed consent was obtained from all study participants.

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Background: BNT162b2 was shown to be 92% effective in preventing COVID-19. Prioritizing vaccine rollout, and achievement of herd immunity depend on SARS-CoV-2 transmission reduction. The vaccine’s effect on infectivity is thus a critical priority. Methods: In a cohort of all 9650 HCW of a large single tertiary medical center, we calculated the prevalence of positive SAR-CoV-2 qRT-PCR cases with an asymptomatic presentation, tested following known or presumed exposure and the infectious subset (N-gene-Ct-value<30) of these and the prevalence of never-symptomatic infections. Additionally, infection incidence rates were calculated for symptomatic cases and infectious (Ct<30) cases. Vaccine effectiveness within three months of vaccine rollout was measured as one minus the relative risk or rate ratio, respectively. To further assess infectiousness, we compared the mean Ct-value and the proportion of infections with a positive SARS-CoV-2 antigen test of vaccinated vs. unvaccinated. The correlation between IgG levels within the week before detection and Ct level was assessed. Findings: Reduced prevalence among fully vaccinated HCW was observed for (i) infections detected due to exposure, with asymptomatic presentation (VE(i)=65.1%, 95%CI 45-79%), (ii) the presumed infectious (Ct<30) subset of these (VE(ii)=69.6%, 95%CI 43-84%) (iii) never-symptomatic infections (VE(iii)=72.3%, 95%CI 48-86%), and (iv) the presumed infectious (Ct<30) subset (VE(iv)=83.0%, 95%CI 51-94%).Incidence of (v) symptomatic and (vi) symptomatic-infectious cases was significantly lower among fully vaccinated vs. unvaccinated individuals (VE(v)= 89.7%, 95%CI 84-94%, VE(vi)=88.1%, 95%CI 80-95%).The mean Ct-value was significantly higher in vaccinated vs. unvaccinated (27.3±1.2 vs. 22.2±1.0, p<0.001) and the proportion of positive SARS-CoV-2 antigen tests was also significantly lower among vaccinated vs. unvaccinated PCR-positive HCW (80% vs. 31%, p<0.001). Lower infectivity was correlated with higher IgG concentrations (R=0.36, p=0.01). Interpretation: These results suggest that BNT162b2 is moderately to highly effective in reducing infectivity, via preventing infection and through reducing viral shedding. Funding: Sheba Medical Center, Israel Declaration of Interest: All authors declare they have no competing interests Ethical Approval: The Sheba Ethical committee, reviewed the protocol and approved the study.

BackgroundBNT162b2 was shown to be 92% effective in preventing COVID-19. Prioritizing vaccine rollout, and achievement of herd immunity depend on SARS-CoV-2 transmission reduction. The vaccine's effect on infectivity is thus a critical priority.MethodsAmong all 9650 HCW of a large tertiary medical center in Israel, we calculated the prevalence of positive SARS-CoV-2 qRT-PCR cases with asymptomatic presentation, tested following known or presumed exposure and the infectious subset (N-gene-Ct-value<30) of these. Additionally, infection incidence rates were calculated for symptomatic cases and infectious (Ct<30) cases. Vaccine effectiveness within three months of vaccine rollout was measured as one minus the relative risk or rate ratio, respectively. To further assess infectiousness, we compared the mean Ct-value and the proportion of infections with a positive SARS-CoV-2 antigen test of vaccinated vs. unvaccinated. The correlation between IgG levels within the week before detection and Ct level was assessed.FindingsReduced prevalence among fully vaccinated HCW was observed for (i) infections detected due to exposure, with asymptomatic presentation (VE(i)=65.1%, 95%CI 45-79%), (ii) the presumed infectious (Ct<30) subset of these (VE(ii)=69.6%, 95%CI 43-84%) (iii) never-symptomatic infections (VE(iii)=72.3%, 95%CI 48-86%), and (iv) the presumed infectious (Ct<30) subset (VE(iv)=83.0%, 95%CI 51-94%).Incidence of (v) symptomatic and (vi) symptomatic-infectious cases was significantly lower among fully vaccinated vs. unvaccinated individuals (VE(v)= 89.7%, 95%CI 84-94%, VE(vi)=88.1%, 95%CI 80-95%).The mean Ct-value was significantly higher in vaccinated vs. unvaccinated (27.3±1.2 vs. 22.2±1.0, p<0.001) and the proportion of positive SARS-CoV-2 antigen tests was also significantly lower among vaccinated vs. unvaccinated PCR-positive HCW (80% vs. 31%, p<0.001). Lower infectivity was correlated with higher IgG concentrations (R=0.36, p=0.01).InterpretationThese results suggest that BNT162b2 is moderately to highly effective in reducing infectivity, via preventing infection and through reducing viral shedding.FundingSheba Medical Center, Israel

OBJECTIVE:To assess reasons for noncompliance with COVID-19 vaccination among healthcare workers (HCWs). DESIGN:Cohort observational and surveillance study. SETTING:Sheba Medical Center, a 1,600-bed tertiary-care medical center in Israel. PARTICIPANTS:The study included 10,888 HCWs including all employees, students, and volunteers. INTERVENTION:The BNT162b2 mRNA COVID-19 vaccine was offered to all HCWs of the hospital. Noncompliance was assessed, and pre-rollout and post-rollout surveys were conducted. Data regarding uptake of the vaccine as well as demographic data and compliance with prior influenza vaccination were collected, and 2 surveys were distributed. The survey before the rollout pertained to the intention to receive the vaccine, and the survey after the rollout pertained to all unvaccinated HCWs regarding causes of hesitancy. RESULTS:In the pre-rollout survey, 1,673 (47%) of 3,563 HCWs declared their intent to receive the vaccine. Overall, 8,108 (79%) HCWs received the COVID-19 vaccine within 40 days of rollout. In a multivariate logistic regression model, the factors that were significant predictors of vaccine uptake were male sex, age 40-59 years, occupation (paramedical professionals and doctors), high socioeconomic level, and compliance with flu vaccine. Among 425 unvaccinated HCWs who answered the second survey, the most common cause for hesitancy was the risk during pregnancy (31%). CONCLUSIONS:Although vaccine uptake among HCWs was higher than expected, relatively low uptake was observed among young women and those from lower socioeconomic levels and educational backgrounds. Concerns regarding vaccine safety during pregnancy were common and more data about vaccine safety, especially during pregnancy, might improve compliance.

A rapid and broad immune response to the third BNT162b2 dose in 208 individuals aged >60 years is reported (33-fold and 51-fold increase in IgG and neutralizing antibody, respectively). Levels post-third dose were significantly higher than post-second dose. Background Despite high vaccine coverage, an increase in breakthrough coronavirus disease 2019 (COVID-19) infections, prompted administration of a third BNT162b2 dose to people aged >60 years in Israel since July 2021. Here, we report real-world immunogenicity following third dose. Methods Overall, 208 healthcare workers aged >60 years were included. Paired pre- and post-second and/or third dose immunoglobulin G (IgG) and neutralizing antibody titers were compared. A subpopulation of low responders to the second dose was also tested for T-cell activation. For 25 paired serum samples, we tested neutralization of wild-type vs neutralization of Delta and Lambda variants, pre- and post-third dose. Active surveillance of vaccine adverse events was conducted through surveys. Results A pronounced immune response was observed following the third dose, including a 33-fold and 51-fold increase in IgG and neutralizing antibody, respectively. The neutralizing antibody levels post-third dose were 9.34 times higher than post-second dose (geometric mean titer, 2598 [95% confidence interval {CI}, 2085-3237] vs 207 [95% CI, 126-339]). Nine previously low responders had a significant antibody increase post-third dose, and 7 of 9 showed increase in T-cell activation. Additionally, sera obtained post-third dose highly and comparably neutralized the wild-type and Delta and Lambda variants. Of 1056 responders to the adverse-event survey, none had serious events. Conclusions We demonstrate a rapid and broad immune response to the third BNT162b2 dose in individuals >60 years of age.

BackgroundConcurrent with the Pfizer–BioNTech BNT162b2 COVID-19 vaccine roll-out in Israel initiated on Dec 19, 2020, we assessed the early antibody responses and antibody kinetics after each vaccine dose in health-care workers of different ages and sexes, and with different comorbidities.MethodsWe did a prospective, single-centre, longitudinal cohort study at the Sheba Medical Centre (Tel-Hashomer, Israel). Eligible participants were health-care workers at the centre who had a negative anti-SARS-CoV-2 IgG assay before receiving the first dose of the intramuscular vaccine, and at least one serological antibody test after the first dose of the vaccine. Health-care workers with a positive SARS-CoV-2 PCR test before vaccination, a positive anti-SARS-CoV-2 IgG serology test before vaccination, or infection with COVID-19 after vaccination were excluded from the study. Participants were followed up weekly for 5 weeks after the first vaccine dose; a second dose was given at week 3. Serum samples were obtained at baseline and at each weekly follow-up, and antibodies were tested at 1–2 weeks after the first vaccine dose, at week 3 with the administration of the second vaccine dose, and at weeks 4–5 (ie, 1–2 weeks after the second vaccine dose). Participants with comorbidities were approached to participate in an enriched comorbidities subgroup, and at least two neutralising assays were done during the 5 weeks of follow-up in those individuals. IgG assays were done for the entire study population, whereas IgM, IgA, and neutralising antibody assays were done only in the enriched comorbidities subgroup. Concentrations of IgG greater than 0·62 sample-to-cutoff (s/co) ratio and of IgA greater than 1·1 s/co, and titres of neutralising antibodies greater than 10 were considered positive. Scatter plot and correlation analyses, logistic and linear regression analyses, and linear mixed models were used to investigate the longitudinal antibody responses.FindingsBetween Dec 19, 2020, and Jan 30, 2021, we obtained 4026 serum samples from 2607 eligible, vaccinated participants. 342 individuals were included in the enriched comorbidities subgroup. The first vaccine dose elicited positive IgG and neutralising antibody responses at week 3 in 707 (88·0%) of 803 individuals, and 264 (71·0%) of 372 individuals, respectively, which were rapidly increased at week 4 (ie, 1 week after the second vaccine dose) in 1011 (98·4%) of 1027 and 357 (96·5%) of 370 individuals, respectively. Over 4 weeks of follow-up after vaccination, a high correlation (r=0·92) was detected between IgG against the receptor-binding domain and neutralising antibody titres. First-dose induced IgG response was significantly lower in individuals aged 66 years and older (ratio of means 0·25, 95% CI 0·19–0·31) and immunosuppressed individuals (0·21, 0·14–0·31) compared with individuals aged 18·00–45·99 years and individuals with no immunosuppression, respectively. This disparity was partly abrogated following the second dose. Overall, endpoint regression analysis showed that lower antibody concentrations were consistently associated with male sex (ratio of means 0·84, 95% CI 0·80–0·89), older age (ie, ≥66 years; 0·64, 0·58–0·71), immunosuppression (0·44, 0·33–0·58), and other specific comorbidities: diabetes (0·88, 0·79–0·98), hypertension (0·90, 0·82–0·98), heart disease (0·86, 0·75–1·00), and autoimmune diseases (0·82, 0·73–0·92).InterpretationBNT162b2 vaccine induces a robust and rapid antibody response. The significant correlation between receptor-binding domain IgG antibodies and neutralisation titres suggests that IgG antibodies might serve as a correlate of neutralisation. The second vaccine dose is particularly important for older and immunosuppressed individuals, highlighting the need for timely second vaccinations and potentially a revaluation of the long gap between doses in some countries. Antibody responses were reduced in susceptible populations and therefore they might be more prone to breakthrough infections.FundingSheba Medical Center, Israel Ministry of Health.

BACKGROUND:Despite high vaccine coverage and effectiveness, the incidence of symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been increasing in Israel. Whether the increasing incidence of infection is due to waning immunity after the receipt of two doses of the BNT162b2 vaccine is unclear. METHODS:We conducted a 6-month longitudinal prospective study involving vaccinated health care workers who were tested monthly for the presence of anti-spike IgG and neutralizing antibodies. Linear mixed models were used to assess the dynamics of antibody levels and to determine predictors of antibody levels at 6 months. RESULTS:The study included 4868 participants, with 3808 being included in the linear mixed-model analyses. The level of IgG antibodies decreased at a consistent rate, whereas the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter. Although IgG antibody levels were highly correlated with neutralizing antibody titers (Spearman's rank correlation between 0.68 and 0.75), the regression relationship between the IgG and neutralizing antibody levels depended on the time since receipt of the second vaccine dose. Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75), lower among persons 65 years of age or older than among those 18 to less than 45 years of age (ratio of means, 0.58; 95% CI, 0.48 to 0.70), and lower among participants with immunosuppression than among those without immunosuppression (ratio of means, 0.30; 95% CI, 0.20 to 0.46). CONCLUSIONS:Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.

In a prospective cohort study involving 12,413 Health Care Workers (HCW), we assessed immunogenicity, vaccine-effectiveness (VE) and safety of the third BNT162b2 vaccine dose. One month after third dose, anti-RBD-IgG were induced 1.7-folds compared to one month after the second. A significant increase in avidity from 61.1% (95%CI:56.1-66.7) to 96.3% (95%CI:94.2-98.5) resulted in a 6.1-folds neutralizing antibodies induction. Linear mixed model demonstrated that the third dose elicited a greater response among HCW[≥]60 or those with [≥]two comorbidities who had a lower response following the second dose. VE of the third dose relative to two doses was 85.6% (95% CI, 79.2-90.1%). No serious adverse effects were reported. These results suggest that the third dose is superior to the second dose in both quantity and quality of IgG-antibodies and safely boosts protection from SARS-CoV-2 infection by generating high avidity antibodies to levels that are not significantly different between healthy and vulnerable populations.

Background Several uses of Antigen rapid diagnostic tests (Ag-RDT) have been suggested. Analytical studies reported high specificity yet with lower sensitivity for detecting SARS-CoV-2 compared to qRT-PCR. Here, we present the use of these tests as a decision support tool in several settings. Methods Samples were collected for both Ag-RDT and qRT-PCR in three different clinical settings; 1. Symptomatic patients presenting at the Emergency Departments 2. Asymptomatic patients screened upon hospitalization and 3. Health-care workers (HCW) following SARS-CoV-2 exposure. Positive percent agreement (PPA), negative percent agreement (NPA), positive predictive value (PPV) and negative predictive value (NPV) were calculated. To estimate the association between Ct value, Ag-RDT and the number of days since SARS-CoV-2 exposure or symptomatic COVID-19, a mixed model was applied. Results A total of 5172 samples were obtained from 4595 individuals, with Ag-RDT and qRT-PCR results. Of these, 485 samples were positive by qRT-PCR. The PPA of Ag-RDT was greater for lower Ct values, reaching 93% in cases where Ct value was lower than 25 and 85% where Ct value was lower than 30. PPA was similar between symptomatic and asymptomatic individuals. The NPV and PPV were 96.8% and 99.1%, respectively. We observed a significant correlation between Ct value and time from infection onset (p<0.001). Lower Ct values were significantly associated with a positive Ag-RDT (p=0.01). Conclusions Ag-RDT can be used as a decision support tool in various clinical settings and play a major role in early detection of SARS-CoV-2 infected individuals, highly specific and with high sensitivity to the infectious stage of disease, whether symptomatic or asymptomatic.

Background End-of-life decisions are highly complex socio-normative and ethical phenomena. The goal of this study was to provide an assessment of public opinions in Israel concerning aspects of end-of-life decisions. Methods An online cross sectional study was performed in February 2020. The primary tool including items pertaining to death assistance and truth telling to patients. A sample of 515 participants representative of the adult Israeli population was obtained. Results The majority of participants (71%) supports telling the entire truth to patients even in harsh conditions. Support for truth telling decreases with affiliation to religion, with as little as 40% support among ultra-orthodox. People with vocational education are the least supportive of truth telling. Concerning doctor assisted death, almost half (49%) of the sample were supportive. Opposition is positively associated with religiosity, with 90% of ultra-orthodox and 58% of religious participants opposing doctor-assisted death, compared to only 18% among seculars. Non-Jews were 3.35 times (95%CI: 1.90, 5.91) more likely to oppose doctor assisted death than Jews ( p < .0001). An Interrelationship analysis crossing between attitudes revealed that the largest group (39%) was comprised of participants who support both (“autonomists”). Conclusions Israelis are overwhelmingly supportive of truth telling to patients. In contrast, Israeli public opinions on doctor assisted death are divided. For both attitudes, religiousness plays a crucial role as a catalyst for conservatism and opposition to change. Almost a half of the public is also supportive of an autonomist approach that would allow patients to decide on ending their own lives.