Patterns of COVID-19 pandemic dynamics following deployment of a broad national immunization program

Studies on the real-life impact of the BNT162b2 vaccine, recently authorized for the prevention of coronavirus disease 2019 (COVID-19), are urgently needed. Here, we analysed the temporal dynamics of the number of new COVID-19 cases and hospitalization in Israel following a vaccination campaign initiated on December 20th, 2020. We conducted a retrospective analysis of data originating from the Israeli Ministry of Health (MOH) from March 2020 to February 2021. In order to distill the possible effect of the vaccinations from other factors, including a third lockdown imposed in Israel on January 2021, we compared the time-dependent changes in number of COVID-19 cases and hospitalizations between (1) individuals aged 60 years and older, eligible to receive the vaccine earlier and younger individuals (0-59 years old); (2) early-vaccinated cities compared to late-vaccinated cities; (3) early-vaccinated geographical statistical areas (GSAs) compared to late-vaccinated GSAs; and (4) the current lockdown versus the previous lockdown, imposed on September 2020. By February 6th 2021, 45.3% and 29.7% of the entire Israeli population (89.9% and 80% of individuals older than 60 years old) received the first dose or both doses of the vaccine, respectively, or recovered from COVID-19. In mid-January, the number of COVID-19 cases and hospitalization started to decline, with a larger and earlier decrease among older individuals. This trend was more evident in early-vaccinated compared to late-vaccinated cities. Such a pattern was not observed in the previous lockdown. Our analysis demonstrates evidence for the real-life effectiveness of a national vaccination campaign in Israel on the pandemic dynamics. This report reflects a snapshot of a fast-changing situation. However, we believe our findings have major public health implications in the struggle against the COVID-19 pandemic, including the publics perception of the need for and benefit of nationwide vaccination campaigns. More studies aimed at assessing the effectiveness of vaccination both on the individual and on the population level, with larger followup are needed.