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.
Schematic representation of the T-indipendent mechanism of the PPV 23 vaccine. Polysaccharide antigens, such as pneumococcal antigens contained in PPV23, stimulate pre-existing memory B cells (MBC) towards terminal differentiation into antibody-producing cells.
