Fig. 1. Israel national data of confirmed SARS-CoV-2 infections, and cases of severe COVID-19 during the study timeline, and graphic representation of participants follow-up.

A Weekly incidence numbers, of all Israeli population, SARS-CoV-2 infection (Black line) and severe COVID-19 (Red line), on different scales, between August 2021 and April 2022; the lines are the point estimate of the weekly incidence events. The study periods are demonstrated beneath the graph (Delta period in blue and Omicron in red; the gray represents the time frame excluded from the study due to overlap of the variants). B Sample of participant follow-up time during the two study periods. Each row represents a participant, colored by their vaccination status during follow-up. Third vaccine (green line), second vaccine (orange line), and unvaccinated (blue line). Participants change color when they move between groups.