First indication of the effect of COVID-19 vaccinations on the course of the COVID-19 outbreak in Israel

De-Leon, H.; Calderon-Margalit, R.; Pederiva, F.; Ashkenazy, Y.; Gazit, D.

Concomitantly with rolling out its rapid COVID-19 vaccine program, Israel is experiencing its third, and so far largest, surge in morbidity. We aimed to estimate whether the high vaccine coverage among individuals aged over 60 years old creates an observable change in disease dynamics. Using observed and simulated data, we suggest that the shape of the outbreak as measured by daily new moderate and severe cases, and in particular of patients aged over 60, has changed because of vaccination, bringing the decline in new moderate and severe cases earlier than expected, by about a week. Our analyses is consistent with the assumption that vaccination lead to higher than 50% protection in preventing clinical disease and with at least some effectiveness in blocking transmission of elderly population, and supports the importance of prioritizing vulnerable population . This is the first indication of the effectivity of COVID-19 vaccine in changing the course of an ongoing pandemic outbreak.