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.
I n May 2021, the US Food and Drug Administration and the European Medicines Agency expanded existing authorization for BNT162b2 vaccine (Pfi zer-BioNTech, https://www.pfi zer.com) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to include its use in adolescents 12-15 years of age (1,2). On June 2, 2021, the Israel Ministry of Health declared the availability of BNT162b2 vaccine for adolescents 12-15 years of age (3) as a 2-dose regimen, given 21 days apart. By August 26, 2021, a total of 277,218 adolescents (46.1% of those eligible) had received 1 dose of the vaccine and 187,707 (31.2%) had received 2 doses (Figure 1, panel A). In mid-June 2021, after a month of extremely low SARS-CoV-2 activity in Israel, 2 local outbreaks erupted (4-6). These outbreaks marked the beginning of a new widespread SARS-CoV-2 outbreak in Israel (Figure 1, panel B), dominated by the B.1.617.2 (Delta) variant, which accounted for 93%-99% of the sequenced viruses during July and August 2021 (7). We analyzed effectiveness of this vaccine among adolescents who had been vaccinated in the early stages of this outbreak in Israel.The study was approved by the superior ethical committee of the Israel Ministry of Health and included exemption from informed consent.
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 22À28 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 15À21 day period after the second dose, ranging between 97.7% (95% CI: 95.9À98.7%) for deaths and 98.6% (95% CI: 97.8À99.1%) for severe/critical disease. VE estimates of the 14À20 day period after the first dose ranged between 54.3% (95% CI: 50.6À57.8%) for infection and 77.3% (95% CI: 71.2À82.1%) for severe/critical disease. VE rose more slowly among 80 year old individuals. Rate reductions of breakthrough complications were highest at the 22À28 day period after the second dose, ranging between 47.4% (95% CI: 4.3À71.2%) for death and 66.2% (95% CI: 44.2À79.6%) 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.
Type 1 diabetes incidence of Jews and Arabs in Israel is increasing. The incidence is higher in Jews than in Arabs; however, the annual percent change is higher in Arabs than in Jews. In both Ethnic groups the incidence of type 1 diabetes is increasing especially among young children.
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