Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Association of COVID-19 vaccination and prior SARS-CoV-2 infection with the risk of infection with the Delta and Omicron variants. The odds ratio estimates are indicated by square symbols and the 95% confidence intervals (CI) are shown by horizontal lines.
