Salmonella typhi Ty21a antigen

Salmonella typhi Ty21a antigens refer collectively to the array of bacterial components present in the live attenuated oral typhoid vaccine strain known as "Ty21a." This preparation contains all major surface structures and internal proteins typical for wild-type Salmonella enterica serovar Typhi except for the Vi capsular polysaccharide, which is absent in this strain. The main immunogenic components include lipopolysaccharide (LPS) O-antigen, flagellar H-d antigen, and other outer membrane proteins. Upon oral administration, these antigens stimulate both humoral and cell-mediated immune responses that mimic natural infection but without causing disease. The induced immunity involves gut-homing T cells and B cells that produce antibodies against S. Typhi LPS and other surface structures; these responses are associated with protection from subsequent exposure to virulent S. Typhi strains.

Other names

Ty21a antigensSalmonella enterica serovar Typhi Ty21a antigensS. Typhi Ty21a vaccine antigens

Induction of protective immune responses via presentation of multiple S. Typhi antigens to the host immune system