Myocarditis after BNT162b2 mRNA Vaccine against Covid-19 in Israel.

BACKGROUND: Approximately 5.1 million Israelis had been fully immunized against coronavirus disease 2019 (Covid-19) after receiving two doses of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) by May 31, 2021. After early reports of myocarditis during adverse events monitoring, the Israeli Ministry of Health initiated active surveillance. METHODS: We retrospectively reviewed data obtained from December 20, 2020, to May 31, 2021, regarding all cases of myocarditis and categorized the information using the Brighton Collaboration definition. We analyzed the occurrence of myocarditis by computing the risk difference for the comparison of the incidence after the first and second vaccine doses (21 days apart); by calculating the standardized incidence ratio of the observed-to-expected incidence within 21 days after the first dose and 30 days after the second dose, independent of certainty of diagnosis; and by calculating the rate ratio 30 days after the second dose as compared with unvaccinated persons. RESULTS: Among 304 persons with symptoms of myocarditis, 21 had received an alternative diagnosis. Of the remaining 283 cases, 142 occurred after receipt of the BNT162b2 vaccine; of these cases, 136 diagnoses were definitive or probable. The clinical presentation was judged to be mild in 129 recipients (95%); one fulminant case was fatal. The overall risk difference between the first and second doses was 1.76 per 100,000 persons (95% confidence interval [CI], 1.33 to 2.19), with the largest difference among male recipients between the ages of 16 and 19 years (difference, 13.73 per 100,000 persons; 95% CI, 8.11 to 19.46). As compared with the expected incidence based on historical data, the standardized incidence ratio was 5.34 (95% CI, 4.48 to 6.40) and was highest after the second dose in male recipients between the ages of 16 and 19 years (13.60; 95% CI, 9.30 to 19.20). The rate ratio 30 days after the second vaccine dose in fully vaccinated recipients, as compared with unvaccinated persons, was 2.35 (95% CI, 1.10 to 5.02); the rate ratio was again highest in male recipients between the ages of 16 and 19 years (8.96; 95% CI, 4.50 to 17.83), with a ratio of 1 in 6637. CONCLUSIONS: The incidence of myocarditis, although low, increased after the receipt of the BNT162b2 vaccine, particularly after the second dose among young male recipients. The clinical presentation of myocarditis after vaccination was usually mild.

Menopausal symptoms and attitudes toward hormone replacement therapy among Israeli women.

Menopause occurs around midlife and is an inevitable component of women's aging. The study aimed to investigate the associations between the lifetime prevalence of menopausal symptoms and health-related characteristics among Israeli postmenopausal women aged 55-75 years. Additionally, this study aimed to estimate the use of hormone replacement therapy (HRT) and women's attitudes toward this treatment. Data for this study were extracted from a cross-sectional national telephone survey conducted in Israel between 2018 and 2020. For the current study, only postmenopausal women aged 55-75 years were included. Multivariate analyses were used to identify demographic and health-related characteristics associated with menopausal symptoms. The study included 688 participants. Most (68.8%) reported one or more menopausal symptoms, specifically vasomotor symptoms (50.4%). According to the multivariate logistic regression analysis, menopausal symptoms were associated with moderate-high anxiety and/or depression symptoms (OR = 2.01, 95% CI 1.12-3.58) and with osteoporosis (OR = 1.78, 95% CI 1.08-2.92). Although most (78.3%) symptomatic women were bothered by their symptoms, 29.1% received any treatment for symptom relief and only 12.6% reported current or past use of HRT. The findings show that menopausal symptoms were associated with a higher prevalence of anxiety and/or depression symptoms and osteoporosis in the years following menopause. Most symptomatic women did not receive any treatment and the majority were against HRT. Knowledge and awareness about menopause and treatment options should be increased among Israeli women. Additionally, the promotion of positive attitudes toward menopause and HRT use among women and healthcare providers is strongly recommended.

Vaccine Coverage Associated With Ending a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Wave: A Retrospective Longitudinal Analysis.

BACKGROUND: Two SARS-CoV-2 waves in Israel ended while a substantial number of individuals remained unvaccinated or partially vaccinated. The indirect protective effect of the first BNT162b2 vaccination campaign in Israel was evaluated between 22 December 2020 and 18 May 2021. METHODS: The daily percentage of new polymerase chain reaction (PCR)-confirmed SARS-CoV-2 cases among unvaccinated individuals was analyzed for trends. Major shifts were identified using piecewise linear regression analysis. At these shifts, the percentage of naturally vaccinated (past SARS-CoV-2 cases) and the percentage of actively vaccinated (by inoculation) individuals were weighted and summed to determine the percentage of natural and active vaccination (NAV). RESULTS: A first decline among unvaccinated individuals occurred during a lockdown period, when the percentage of NAV was 8.16%. The major decline occurred after the end of the lockdown when the percentage of NAV reached 52.05%. SARS-CoV-2 cases ultimately declined among unvaccinated individuals when the percentage of NAV reached 63.55%. During the study period, the Alpha variant was prevalent and the use of nonpharmaceutical interventions, including social distancing, existed to varying degrees. CONCLUSIONS: The vaccination campaign played a major role in the decline of SARS-CoV-2 infection among unvaccinated individuals, leading to the end of the first 2021 SARS-CoV-2 wave (Alpha variant) in Israel. Infection in unvaccinated individuals stopped when two-thirds of the population were naturally or actively vaccinated. Any change in characteristics of the virus or the population can lead to a new outbreak.

Effectiveness of BNT162b2 Vaccine against Omicron Variant Infection among Children 5-11 Years of Age, Israel.

We assessed effectiveness of the BNT162b2 vaccine against infection with the B.1.1.529 (Omicron) variant (mostly BA.1 subvariant), among children 5-11 years of age in Israel. Using a matched case-control design, we matched SARS-CoV-2-positive children (cases) and SARS-CoV-2-negative children (controls) by age, sex, population group, socioeconomic status, and epidemiologic week. Vaccine effectiveness estimates after the second vaccine dose were 58.1% for days 8-14, 53.9% for days 15-21, 46.7% for days 22-28, 44.8% for days 29-35, and 39.5% for days 36-42. Sensitivity analyses by age group and period demonstrated similar results. Vaccine effectiveness against Omicron infection among children 5-11 years of age was lower than vaccine efficacy and vaccine effectiveness against non-Omicron variants, and effectiveness declined early and rapidly.

Attention-deficit hyperactivity disorder is associated with disordered eating in adolescents.

AIM: Attention-deficit hyperactivity disorder (ADHD) and disordered eating (DE) are both highly prevalent among adolescents, but their relationship is understudied. This study examines their possible association in a nationally representative sample of adolescents. METHODS: Participants in the Israeli Youth Health and Nutrition Survey (2015-2016), a cross-sectional, school-based study, completed self-administered questionnaires, including the SCOFF questionnaire, and underwent anthropometric measurements. An affirmative reply to at least two SCOFF items was considered a DE case. Multivariable logistic regression evaluated the ADHD-DE association and the associations between ADHD and individual SCOFF items, controlling for age, sex, socioeconomic status, and body mass index. RESULTS: Of 4616 participants (12-18 years, 50.2% male), 654 reported an ADHD diagnosis. DE prevalence among ADHD adolescents was significantly higher than the non-ADHD group (50.2% vs. 43.9%, p = 0.003). Controlling for potential covariates, the association between ADHD and DE remained significant (OR = 1.409; 95% CI: 1.170-1.697), as did associations between ADHD and three SCOFF items. No difference in DE prevalence was found between stimulant-treated (n = 287) and untreated (n = 326) adolescents with ADHD. CONCLUSION: Adolescents with ADHD are more likely to experience DE. As DE can herald an imminent eating disorder, early identification is crucial. Further studies are needed to determine the ADHD-DE relationship's causality. IMPACT: Disordered eating (DE) and attention-deficit hyperactivity disorder (ADHD) are common among adolescents, and significantly affect health and well-being. This study examined the association between ADHD and DE in adolescents using the SCOFF questionnaire. Following adjustment for sociodemographic variables and BMI z-score, ADHD was associated with a 41% increased odds for DE. This study established the association between ADHD and DE, using a well-known questionnaire, in a large, nationally representative sample of adolescents. Monitoring eating behaviors and attitudes among adolescents with ADHD should be a priority, to minimize the risk of developing an eating disorder and its harmful consequences.

Attention-deficit hyperactivity disorder is associated with relatively short stature among adolescents.

AIM: To estimate the association between attention-deficit hyperactivity disorder (ADHD) and relatively short stature (RSS) among adolescents. METHODS: Participants in the Israeli Youth Health and Nutrition Survey (2015-2016), a cross-sectional school-based study, completed self-administered questionnaires and underwent anthropometric measurements. Height z-score < -0.7 (<25th percentile) was defined as RSS. Multivariable logistic regression analyses assessed the relation between ADHD and RSS, controlling for age, sex, body mass index (BMI) and socioeconomic status (Basic Model), and also for lifestyle factors such as physical activity, sleep duration, dietary patterns and intakes. RESULTS: Of 4173 participants (11-18 years, 50.2% males), 654 self-reported ever being diagnosed with ADHD; 3519 participants were controls. Overweight (BMI z-score ≥1) and pubertal status were not different among groups. According to the Basic Model, ADHD was significantly associated with RSS (OR 1.25, 95% CI 1.03-1.50), and even after adjustments for lifestyle factors and dietary intake (OR 1.28, 95% CI 1.03-1.58). Stimulant-treated ADHD adolescents had similar height z-scores and lifestyles as those not treated with stimulants. CONCLUSION: Attention-deficit hyperactivity disorder was associated with RSS. Height deficit may be intrinsic to ADHD or its pharmacotherapy, rather than a consequence of lifestyle alone. Further studies are needed to determine the causal relationship between ADHD and short stature.

Rise in depression and anxiety during the COVID-19 pandemic: results from a cross-sectional national survey.

The Coronavirus disease 2019 (COVID-19) pandemic has introduced many mental stressors. This study aimed to evaluate the prevalence of depression and anxiety during the pandemic and characterize those at higher risk. We conducted a national cross-sectional telephone interview survey among Israeli adults from May to September 2020, between the first two national lockdowns. Mental health status was measured using the 5-item Mental Health Inventory (MHI-5). A score of ≤60 was defined as poor mental health with moderate to high anxiety and depression symptoms. Multivariate analysis was used to identify demographic, health-related, and COVID-19-related risk factors associated with poor mental health. From 4,712 households that were eligible for inclusion in this study, 2,634 participants (55.9%) completed the survey. Levels of anxiety and depression symptoms increased significantly throughout the pandemic (from 12.9% to 20.3%, P < 0.001). Loneliness also increased over time (from 48.8% to 58.8%, P < 0.001), and fear of the pandemic remained high (66.5%) throughout the study. According to the multivariate analysis, poor mental health was associated with younger age, female gender, lower education, Arab ethnicity, decrease in household income during the pandemic, having a pre-existing chronic illness, obesity, smoking, ever being quarantined, feeling lonely and fear of the pandemic. Our findings show an increase in anxiety and depression over time among the Israeli population during the COVID-19 pandemic. These findings highlight the need for strengthened mental health services and the flexibility of reallocation of funds and health resources to support the growing mental health needs during the health crisis.

Effectiveness of BNT162b2 Vaccine Booster against SARS-CoV-2 Infection and Breakthrough Complications, Israel.

We estimated vaccine effectiveness (VE) of the BNT162b2 (Pfizer-BioNTech, https://www.pfizer.com) booster dose against SARS-CoV-2 infection and reduction of complications (hospitalization, severe disease, and death) among breakthrough cases in persons in Israel >16 years of age for <20 weeks. VE estimates reached 96.8% (95% CI 96.0%-97.5%) for persons 16-59 years of age and 93.1% (95% CI 91.8%-94.2%) for persons >60 years of age on week 3. VE estimates remained at these levels for 8 weeks in the 16-59 age group and 11 weeks in those >60. A slow decline followed, becoming more pronounced in the last 2-3 weeks of evaluation. Estimates in the last week of evaluation were 77.6% (95% CI 68.4%-84.2%) and 61.3% (52.5%-68.4%) for persons 16-59 years and >60 years, respectively. The more pronounced VE decline coincided with rapid increase in Omicron variant activity. Rate reduction of breakthrough complications remained moderate to high throughout the evaluation.

The impact of SARS-CoV-2 on respiratory syndromic and sentinel surveillance in Israel, 2020: a new perspective on established systems.

BackgroundThe COVID-19 pandemic presented new challenges for the existing respiratory surveillance systems, and adaptations were implemented. Systematic assessment of the syndromic and sentinel surveillance platforms during the pandemic is essential for understanding the value of each platform in the context of an emerging pathogen with rapid global spread.AimWe aimed to evaluate systematically the performance of various respiratory syndromic surveillance platforms and the sentinel surveillance system in Israel from 1 January to 31 December 2020.MethodsWe compared the 2020 syndromic surveillance trends to those of the previous 3 years, using Poisson regression adjusted for overdispersion. To assess the performance of the sentinel clinic system as compared with the national SARS-CoV-2 repository, a cubic spline with 7 knots and 95% confidence intervals were applied to the sentinel network's weekly percentage of positive SARS-CoV-2 cases.ResultsSyndromic surveillance trends changed substantially during 2020, with a statistically significant reduction in the rates of visits to physicians and emergency departments to below previous years' levels. Morbidity patterns of the syndromic surveillance platforms were inconsistent with the progress of the pandemic, while the sentinel surveillance platform was found to reflect the national circulation of SARS-CoV-2 in the population.ConclusionOur findings reveal the robustness of the sentinel clinics platform for the surveillance of the main respiratory viruses during the pandemic and possibly beyond. The robustness of the sentinel clinics platform during 2020 supports its use in locations with insufficient resources for widespread testing of respiratory viruses.

Current use of nutrition facts tables and attitudes towards new red and green front-of-package labels among Israeli consumers.

Front-of-package labels (FOPL) are designed to simplify nutrition information and to help consumers make healthier food choices. The Israeli government has implemented new regulations requiring mandatory red warning FOPL for high levels of sodium, sugar, or saturated fats. A voluntary green positive FOPL for products fitting the national nutritional recommendations was concurrently encouraged. In order to characterise adult consumers' current use of Nutrition Facts Tables (NFT) and their attitudes towards the new FOPL, a nationally representative cross-sectional telephone survey was conducted. Most of the 1,042 survey respondents reported frequent NFT use (76.2%) and intentions to purchase fewer red-labelled (81.1%) and more green-labelled products (85.0%). Consumers with higher BMI and lower education expressed higher intentions to use the new FOPL, but not higher current use of NFT. This finding suggests that these high-risk groups, which the new labels are meant to target, may indeed benefit from the new policy.

Monitoring SARS-CoV-2 Activity with Sentinel Surveillance: Lessons Learned from the First Wave in Israel.

BACKGROUND: Guidelines for pandemic preparedness emphasize the role of sentinel and syndromic surveillance in monitoring pandemic spread. OBJECTIVES: To examine advantages and obstacles of utilizing a sentinel influenza surveillance system to monitor community severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) activity based on Israel's experience from mid-March to mid-May 2020. METHODS: Several modifications were applied to the influenza surveillance system. The clinical component relied mainly on pneumonia and upper respiratory infection (URI) consultations with primary care physicians as well as visits to emergency departments (ED) due to pneumonia. The virological data were based on nasopharyngeal swabs obtained from symptomatic patients who visited outpatient clinics. RESULTS: By week 12 of the pandemic, the crude and age-specific primary physician consultation rates due to URI and pneumonia declined below the expected level, reaching nadir that lasted from week 15 until week 20. Similarly, ED visits due to pneumonia were significantly lower than expected from weeks 14 and 15 to week 20. The virological surveillance started on week 13 with 6/253 of the swabs (2.3%) positive for SARS-CoV-2. There was a peak of 13/225 positive swabs on week 145.8%. During weeks 17-20, none of the swabs (47-97 per week) were positive for SARS-CoV-2. This trend was similar to national data. CONCLUSIONS: The virological component of the surveillance system showed the SARS-CoV-2 community spread, but had low sensitivity when virus activity was low. The clinical component, however, had no yield. Sentinel surveillance can assist in monitoring future novel pandemics and should be augmented in revised preparedness plans.

Effectiveness of BNT162b2 Vaccine in Adolescents during Outbreak of SARS-CoV-2 Delta Variant Infection, Israel, 2021.

In Israel, the BNT162b2 vaccine against severe acute respiratory syndrome coronavirus 2 was approved for use in adolescents in June 2021, shortly before an outbreak of B.1.617.2 (Delta) variant-dominant infection. We evaluated short-term vaccine effectiveness and found the vaccine to be highly effective among this population in this setting.

Significant cross reactive antibodies to influenza virus in adults and children during a period of marked antigenic drift.

BACKGROUND: Little is known about the development of cross-reactive antibodies following natural exposure to pathogens. Such knowledge is critical in the development of new universal influenza vaccines. METHODS: To study the possibility of the presence of cross-reactive antibodies to influenza viruses which underwent a major antigenic drift between the years 1999 and 2007 sera from samples of 80 children and 400 adults were selected at random from the Israeli national serum bank. The sera was obtained in 2002 and in 2007, two time points that followed a major drift in the infectious H3N2 influenza virus strain (A/Panama/2007/99 to A/Wisconsin/67/2005). RESULTS: In the summer of 2002, 13% of the children had Hemagglutination Inhibition (HI) antibody titers of at least 40 and these antibodies recognized both A/Panama/2007/99 and A/Wisconsin/67/2005, where the latter strain only began to circulate in Israel in 2006. In 2007, 29% of the children had HI antibody titers of at least 40 directed against both A/Wisconsin/67/2005 and A/Panama/2007/99, even though they had never been exposed to the latter virus. Anti-A/Panama/2007/99 antibodies were detected in 58% and 68% of the 2002 and 2007 adult samples, respectively, while 8% and 39% had antibodies against A/Wisconsin/67/2005, respectively. CONCLUSIONS: The presence of naturally occurring cross-reactive influenza virus antibodies in a significant percentage of children has important implications for the development of a universal influenza vaccine.

COVID-19 vaccine hesitancy among Israeli adults before and after vaccines' availability: A cross-sectional national survey.

Vaccine hesitancy (VH) is a major health threat to the efforts to tackle COVID-19 morbidity and mortality. This study's objectives were to assess COVID-19VH before and after vaccines' availability and to analyze the associations between COVID-19VH and participants' characteristics. A national cross-sectional telephone interview survey among Israeli adults aged 21 and older was conducted from September 2020 through May 2021. Attitudes towards COVID-19 vaccines were assessed pre/post vaccines' availability. Multivariate logistic regression analyses were used to identify associations between demographic and health-related characteristics and COVID-19 VH. Most study participants (72.0 % of 2,998) were willing to be vaccinated against COVID-19 across the survey period. The COVID-19 VH declined significantly from 45.6 % pre-vaccine availability to 16.3 % post-vaccine availability (P < 0.001). The multivariable analysis demonstrated that post-vaccine availability, COVID-19 VH was associated with younger age, Arab ethnicity, higher level of religiosity, lower education, past diagnosis of COVID-19, and influenza VH. The main reasons for VH after the vaccine availability included insufficient data on the vaccine (37.4 %) and fear of the vaccine's side effects (33.8 %). Despite the significant decrease in COVID-19 VH following vaccine availability, 16.3% of the population still refuses to get vaccinated. As Israel may face additional waves of the COVID-19 pandemic and booster vaccinations, multimedia vaccine promotions targeting the above-mentioned hesitant populations and their reasons for VH are urgently needed.

Invasive bacterial infections in relation to influenza outbreaks, 2006-2010.

BACKGROUND: We aimed to define the excess morbidity associated with bloodstream infections (BSIs), imposed by pandemic H1N1 influenza during 2009-2010 (pH1N1/2009-2010) and seasonal influenza. METHODS: Eight hospitals, accounting for 33% of hospitalizations in Israel, provided data on BSI during 2006-2010. The age-specific incidence of BSI due to Streptococcus pneumoniae, Staphylococcus aureus, and Streptococcus pyogenes was determined. BSI incidence rate ratios (IRRs) during seasonal and pH1N1 influenza seasons were assessed. RESULTS: Regular influenza seasons were characterized by increased rates of S. pneumoniae BSI but with no increase in S. aureus and S. pyogenes BSI rates. The pH1N1/2009-2010 influenza outbreak was characterized by (1) higher rates of S. pneumoniae bacteremia among children but not among adults (IRRs for S. pneumoniae BSI among children aged 0-4 years during the summer and winter of 2009-2010 were 14.8 [95% confidence interval {CI}, 5-43.7] and 6.5 [95% CI, 3.6-11.8], compared with 2006-2009 summers and influenza-active winter weeks, respectively [P < .0001]), higher rates of S. aureus BSI in all age groups (IRRs during the summer and winter of 2009-2010 were 1.6 [95% CI, 1.4-1.9] and 1.5 [95% CI, 1.2-1.7], compared with 2006-2009 summers and influenza-active weeks, respectively [P < .0001]), higher rates of S. pyogenes BSI during 2009-2010 influenza season (IRR 2.7 [95% CI, 1.6-4.6] and 3.3 [95% CI, 1.9-5.8] during the summer and winter of 2009-2010, compared with 2006-2009 summers and influenza-active weeks, respectively [P < .0001]). CONCLUSIONS: pH1N1 influenza seasons were characterized by marked increases in invasive S. aureus and S. pyogenes infections among children and adults, with the highest increase in S. pneumoniae BSI among children.

Increased extent of and risk factors for pandemic (H1N1) 2009 and seasonal influenza among children, Israel.

During the pandemic (H1N1) 2009 outbreak in Israel, incidence rates among children were 2× higher than that of the previous 4 influenza seasons; hospitalization rates were 5× higher. Children hospitalized for pandemic (H1N1) 2009 were older and had more underlying chronic diseases than those hospitalized for seasonal influenza.

Adenovirus infections in hospitalized patients in Israel: epidemiology and molecular characterization.

Adenoviruses can cause a broad spectrum of clinical diseases, most of which are self-limited. However, adenovirus infection can occasionally result in severe or lethal infection. Fifty-five adenovirus serotypes are known today, and they are classified into 7 subgroups (subgroups A to G). Here we examined 282 samples derived from hospitalized patients in Israel (September 2006 to August 2008) who were diagnosed as suffering from adenovirus infections. We used a recently described PCR amplification method and subsequent sequencing to identify the adenovirus. In addition, we studied the medical charts of 106 hospitalized patients from Sheba Medical Center in Israel. The most prevalent adenovirus serotypes found were serotypes 1 (22.8%), 2 (19.2%), 7 (18%), and 3 (14%). In addition, we identified several serotypes that have not been identified previously in Israel. Overall, serotypes of subgroup B were found to be approximately 4 times more prevalent among immunocompromised children than among generally healthy children (52.6%; P < 0.007). The realization that the virus subtypes are different among healthy and immunocompromised patients may lead to more efficient treatment of adenovirus infections among immunocompromised children in the future.

The BNT162b2 vaccine effectiveness against new COVID-19 cases and complications of breakthrough cases: A nation-wide retrospective longitudinal multiple cohort analysis using individualised data.

BACKGROUND: The rapid vaccination campaign against COVID-19 in Israel relied on the BNT162b2 vaccine. We performed a longitudinal analysis of multiple cohorts, using individual data, to evaluate the effectiveness of the vaccine against new and breakthrough cases. METHODS: We estimated vaccine effectiveness (VE) for 27 consecutive cohorts, each comprised of individuals vaccinated on specific days. VE against new COVID-19 cases was evaluated for five SARS-CoV-2-related outcomes: infection, symptomatic disease, hospitalisation, severe/critical disease and death. For breakthrough cases, rate reduction was evaluated for hospitalisation, severe/critical disease and death. Outcomes were evaluated at predetermined time-periods after vaccination, the last one dedicated to individuals who became SARS-CoV-2-positive 22-28 days after the second dose. FINDINGS: The highest VE estimates against new cases in ≥16 year old individuals, for all outcomes, were reached at the 15-21 day period after the second dose, ranging between 97.7% (95% CI: 95.9-98.7%) for deaths and 98.6% (95% CI: 97.8-99.1%) for severe/critical disease. VE estimates of the 14-20 day period after the first dose ranged between 54.3% (95% CI: 50.6-57.8%) for infection and 77.3% (95% CI: 71.2-82.1%) for severe/critical disease. VE rose more slowly among ≥80 year old individuals. Rate reductions of breakthrough complications were highest at the 22-28 day period after the second dose, ranging between 47.4% (95% CI: 4.3-71.2%) for death and 66.2% (95% CI: 44.2-79.6%) for severe/critical disease. INTERPRETATION: The BNT162 vaccine is highly effective in preventing new SARS-CoV-2 cases. Among ≥80 year old individuals, high effectiveness develops more slowly. In breakthrough cases, vaccination reduces complications and death. FUNDING: None.