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.
[Atlanta] : U.S. Dept. of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention ; [Washington, D.C.] : U.S. G.P.O., [1993]