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.
Protection against challenge in animals receiving two intranasal immunizations with heat-killed S. flexneri 2a strain 2457 or heat-killed 2457T plus native or mutant toxin molecules as adjuvants. Animals were challenged with virulent strain 2457T 4 weeks after the second immunization.
