Quantifying the Population-level Effect of the COVID-19 Mass Vaccination Campaign in Israel: a Modeling Study
2Department of Geography and Division of Epidemiology, The Ohio State University, and Translational Data Analytics Institute Columbus, ארצות הברית
3Israel Center for Disease Control, Israel Ministry of Health, ישראל
4Department of Mathematics, The Ohio State University, ארצות הברית
5School of Medicine, Aurora, University of Colorado ,, ארצות הברית
6Department of Pediatrics, Mayanei Hayeshuah Medical Center, ישראל
Background: Estimating real-world vaccine effectiveness is challenging since a variety of population factors can impact vaccine effectiveness.
We aimed to assess the population-level reduction in cumulative SARS-CoV-2 cases, hospitalizations and mortality due to the BNT162b2 mRNA COVID-19 vaccination campaign in Israel during January-February, 2021.
Methods: An SIR model and a Dynamic Survival Analysis (DSA) statistical approach was used. Daily counts of tested positive and of vaccine doses administered were used to calibrate the model. The model was parameterized using values derived from a previous phase of the pandemic during which similar lockdown and other preventive measures were implemented in order to take into account the effect of these preventing measures on COVID-19 spread.
Results: Our model predicts for the total population a reduction of 648,585 SARS-CoV-2 cases (75% confidence interval [CI]: 25,877–1,396,963) during the first 2 months of the vaccination campaign. The number of averted hospitalizations for moderate – severe conditions were 16,101 (75 % CI: 2,010–33,035) and reduction of death was estimated as 5,123 (CI: 388–10,815) fatalities.
Among children aged 0-19 years, we estimated a reduction of 163,436 (CI: 0–433,233) SARS-CoV-2 cases which we consider as an indirect effect of the vaccine.
Conclusions: Our results suggest that the rapid vaccination campaign prevented hundreds of thousands of new cases as well as thousands of hospitalizations and fatalities and has probably averted a major health care crisis.