Infections, Hospitalizations, and Deaths Averted Via Direct Effects of the Pfizer-BioNTech BNT162b2 mRNA COVID-19 Vaccine in a Nationwide Vaccination Campaign, Israel

Background: Israel recently initiated a rapid nationwide COVID-19 vaccination campaign to immunize persons ≥16 years of age and used exclusively Pfizer–BioNTech BNT162b2 mRNA COVID-19 vaccine according to schedule (two doses, 21 days apart). We provide the first estimates of the number of COVID-19 cases, hospitalizations, and deaths averted by a nationwide vaccination campaign.  Methods: We used national surveillance data from the first 112 days (Dec 20, 2020 ‒ Apr 10, 2021) of Israel’s vaccination campaign to estimate averted burden of four outcomes: SARS-CoV-2 infections and COVID-19-related hospitalizations, severe or critical hospitalizations, and deaths. The direct effects of the immunization program were estimated for all susceptible individuals (i.e., no previous evidence of laboratory-confirmed SARS-CoV-2 infection) who were at least partially vaccinated (defined as receipt of at least one dose with ≥14 days after the first dose). Cases averted were estimated based on cumulative daily, age-specific rate differences comparing rates among unvaccinated to those who were at least partially vaccinated for each of the four outcomes and the (age-specific) size of the susceptible population and proportion that was at least partially vaccinated.  Findings: Through Apr 10, 2021, we estimated that Israel’s vaccination campaign averted 158,665 (95% uncertainty range: 115,899‒201,431) SARS-CoV-2 infections, 24,597 (6,622‒42,571) hospitalizations, 17,432 (3,065‒31,799) severe and critical hospitalizations, and 5,533 (-1,146‒12,213) deaths. Of these, 66% of hospitalizations and 91% of deaths averted were among those ≥65 years of age. Seventy-three percent of SARS-CoV-2 infections and 79% of COVID-19-related hospitalizations and deaths averted stemmed from the protective effects in fully vaccinated persons.  Interpretations: Without vaccination, Israel would have likely experienced triple the number of hospitalizations and deaths compared to what actually occurred during their largest wave of SARS-CoV-2 to date, which would have likely overwhelmed the healthcare system. Indirect effects and long-term benefits of the program, which could be substantial, were not included in these estimates and warrant future research.  Funding: None. Declaration of Interest: John McLaughlin, Frederick Angulo, Farid Khan, Gabriel Mircus, Kaijie Pan, Jo Southern, David Swerdlow, and Luis Jodar hold stock and stock options in Pfizer Inc. Marc Lipsitch has provided advice on COVID-19 free of charge to Janssen, Astra-Zeneca, Pfizer, and COVAXX (United Biomedical), as well as to the nonprofit One Day Sooner and has received consulting income or honoraria from Merck, Bristol Meyers Squibb, and Sanofi, and institutional research support from Pfizer. All other authors report no conflicts.