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.
Statistically significant differences between two successive days post-infection are indicated by asterisks (* = p<0.05; ** = p<0.01; **** = p<0.0001).
