COVID-19 infections in fully vaccinated people are expected as vaccines are not 100% effective in preventing infection. However, they are very effective at preventing severe illness such as those requiring
hospitalization or causing deaths. During the first 4 months of the year, 10,262 breakthrough cases were reported by 46 state and territorial health departments, including 995 hospitalizations and 160 deaths, many of which were reported as asymptomatic or hospitalized for a reason unrelated to COVID-19. Learn more: bit.ly/MMWR52521.
