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.
R5, dual and X4-tropic HIV-2 strains are depicted in continuous, dashed and dotted black lines, respectively. HIV-1 R5-tropic strain is depicted using the continuous gray line.
