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.
A/PR8 (H1N1) virus challenge. Four weeks after the last immunization, mice were infected i.n. with 5 LD50s of mouse-adapted A/PR8 virus (125 PFU). Survival of mouse groups immunized i.m. (A) or i.n. (B) and body weight changes of groups immunized i.m. (C) or i.n. (D) were monitored and recorded as described in the legend to Fig. 4.
