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Pfizer-BioNTech Vaccine Effectiveness Against SARS-CoV-2 Infection: Findings From a Large Observational Study in Israel

18 Pages Posted: 25 Jun 2021

See all articles by Yaki Saciuk

Yaki Saciuk

Maccabi HealthCare Services - Department of Health Evaluation & Research

Jennifer Kertes

Maccabi HealthCare Services - Department of Health Evaluation & Research

Micha Mandel

Hebrew University of Jerusalem - Statistics Department

Beatriz Hemo

Maccabi HealthCare Services - Department of Health Evaluation & Research

Naama Shamir Stein

Maccabi HealthCare Services - Department of Health Evaluation & Research

Anat Ekka Zohar

Maccabi HealthCare Services - Division of Data & Digital Health

More...

Abstract

Background: Development of an effective vaccine against Covid-19 is crucial to reducing infection. mRNA BNT162b2, developed and manufactured by Pfizer-BioNTech, was one of the first FDA-approved vaccinations reporting high efficacy (95%) and minimal side effects. Evaluating effectiveness of mRNA BNT162b2 in a general population has been made possible after the implementation of a nation-wide vaccination program in Israel.

Methods: This retrospective cohort study was carried out in Maccabi HealthCare services, Israel among 1·6 million members aged 16 and over. The population was divided into those who were at least seven days post- second vaccination and those who had not been vaccinated. Number of days till the end of the study or Covid-19 infection, Covid-19-related hospitalization and mortality was calculated for each participant between 18.1.2021 to 25.4.2021. Participants who had reached day eight after second vaccination during the study period could contribute days to both groups. Vaccine efficacy (VE) was calculated using a conditional Poisson model, controlling for age group, gender, hypertension, diabetes and obesity, fitted within clusters defined by geographical statistical area and calendar week.

Findings: mRNA BNT162b2 was found effective for the total population group for infection, hospitalization and mortality, with adjusted VE of 93·0% (CI:92·6-93·4%), 93·4% (CI:91·9-94·7%) and 91·1% (CI:86·5-94·1%) respectively. VE for infection was lower for participants aged 75 and over, and for those with hypertension, diabetes and obesity. Interpretation:This study strengthens the evidence that the Pfizer-BioNTech vaccination is effective in preventing infection, hospitalization and mortality.

Funding: Maccabi HealthCare Services.

Declaration of Interest: No conflict of interests to report. Authors #1,2,4 & 5 are employed by Maccabi HealthCare Services.

Ethical Approval: The study was approved by Maccabi HealthCare Services IRB and Maccabi Helsinki committee (#0178-20-MHS).

Suggested Citation

Saciuk, Yaki and Kertes, Jennifer and Mandel, Micha and Hemo, Beatriz and Shamir Stein, Naama and Zohar, Anat Ekka, Pfizer-BioNTech Vaccine Effectiveness Against SARS-CoV-2 Infection: Findings From a Large Observational Study in Israel. Available at SSRN: https://ssrn.com/abstract=3868853 or http://dx.doi.org/10.2139/ssrn.3868853

Yaki Saciuk

Maccabi HealthCare Services - Department of Health Evaluation & Research ( email )

4 Yehezkel Kaufmann St.
Tel Aviv
Israel

Jennifer Kertes (Contact Author)

Maccabi HealthCare Services - Department of Health Evaluation & Research ( email )

Tel Aviv
Israel

Micha Mandel

Hebrew University of Jerusalem - Statistics Department ( email )

Mount Scopus
Jerusalem, 91905
Israel

Beatriz Hemo

Maccabi HealthCare Services - Department of Health Evaluation & Research ( email )

4 Yehezkel Kaufmann St.
Tel Aviv
Israel

Naama Shamir Stein

Maccabi HealthCare Services - Department of Health Evaluation & Research ( email )

4 Yehezkel Kaufmann St.
Tel Aviv
Israel

Anat Ekka Zohar

Maccabi HealthCare Services - Division of Data & Digital Health ( email )

4 Yehezkel Kaufmann St.
Tel Aviv
Israel