Typhoid conjugate vaccine Vi-DT

The typhoid conjugate vaccine Vi-DT is a next-generation vaccine designed to prevent typhoid fever, a potentially life-threatening illness caused by *Salmonella enterica* serovar Typhi. The vaccine consists of the purified Vi capsular polysaccharide antigen from *S. Typhi* chemically conjugated to diphtheria toxoid as a carrier protein. This conjugation enhances immunogenicity, especially in young children and infants who do not respond well to unconjugated polysaccharide vaccines. The mechanism of action involves stimulating the immune system to produce anti-Vi IgG antibodies and memory B-cell responses against the Vi antigen, providing long-term protection after a single dose. Clinical trials have demonstrated that Vi-DT is safe and highly immunogenic in individuals from 6 months up to 45 years old, with non-inferiority compared to other WHO-prequalified typhoid vaccines such as those using tetanus toxoid as carrier (Vi-TT). The International Vaccine Institute (IVI) developed the technology and transferred it for manufacturing scale-up[1][4][5][6].

Brand names

Bio-TCVSKYTyphoid

Other names

Vi-diphtheria toxoid typhoid conjugate vaccineVi polysaccharide-diphtheria toxoid conjugate vaccine