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.
The letters (a, b, and c) denote blood donors with HBsAg negative and anti-HBc positive, HBsAg negative and anti-HBc negative, and HBsAg negative, respectively. Map source: https://www.datawrapper.de/.
