typhoid polysaccharide vaccine

Vi polysaccharide is a subunit vaccine used for the prevention of typhoid fever caused by *Salmonella enterica* serovar Typhi. It consists of the purified Vi (Virulence) capsular polysaccharide, which is a linear homopolymer of α-1,4-linked N-acetylgalactosaminuronic acid, O-acetylated at the C-3 position. The vaccine works by inducing a T-cell independent B-cell response, resulting in the production of serum IgG antibodies that provide protection against the bacterium. It is typically administered as a single parenteral dose and is indicated for individuals aged two years and older, as it is poorly immunogenic in younger children due to the immature nature of their immune systems regarding polysaccharide antigens. The vaccine is often used in travelers to endemic areas and in populations at high risk of exposure.

Brand names

Typhim ViTypherixVaxityph

Other names

Vi polysaccharideVi capsular polysaccharideSalmonella typhi Vi polysaccharideVi antigen