Vaccine antigens from Vibrio cholerae, Salmonella Typhi Vi polysaccharide-tetanus toxoid conjugate, and live attenuated measles and rubella viruses

This entry describes a heterogeneous group of vaccine antigens derived from bacterial and viral pathogens, including Vibrio cholerae, Salmonella Typhi, and the viruses causing measles and rubella. These antigens are not therapeutic targets in the conventional sense (such as receptors or enzymes) but are immunogenic substances used to stimulate a protective immune response (WHO, 2023). The Vibrio cholerae component typically consists of inactivated whole cells or the recombinant B-subunit of the cholera toxin, which induces mucosal immunity to prevent cholera-induced diarrhea (Clemens et al., 2017). The Salmonella Typhi Vi polysaccharide-tetanus toxoid (Vi-TT) conjugate is a modern vaccine that links the Vi capsular polysaccharide to a tetanus toxoid carrier protein to enhance immunogenicity in infants (WHO, 2018). Measles and rubella components are live attenuated viruses that replicate minimally to stimulate long-lasting humoral and cellular immunity (CDC, 2021). Upon administration, these antigens are processed by antigen-presenting cells and presented to B and T lymphocytes, leading to the production of neutralizing antibodies and memory cells. These vaccines are critical tools in global health for preventing outbreaks and reducing morbidity and mortality associated with these specific infectious agents. Safety profiles are generally favorable, though live attenuated components require caution in pregnant or severely immunocompromised populations (WHO, 2022).

Other names

Cholera vaccine antigensTyphoid conjugate vaccineVi-TTMeasles-Rubella vaccineMR vaccineOral cholera vaccineOCV

These antigens act as immunogens that are processed by antigen-presenting cells and presented to the adaptive immune system, triggering the production of pathogen-specific antibodies and the formation of memory B and T cells to provide long-term protection against subsequent exposure.