Typbar TCV is a vaccine containing polysaccharide of Salmonella typhi Ty2 conjugated to Tetanus Toxoid.
Vi Capsular polysaccharide of Salmonella typhi alone elicit B cell responses, but the conjugation of bacterial polysaccharide to a protein carrier provides foreign peptide antigens that are presented to the immune system eliciting antigen-specific CD4+ Th cells, referred to as T-dependent antibody responses..
Typbar TCV is indicated as a preventative vaccine against Typhoid which is caused by Salmonella Typhi and Paratyphi.
The WHO recently recommended that routine childhood immunization programs include Typbar TCV as a single intramuscular dose for primary vaccination of infants and children from 6 months of age.
It is also recommended for adults ≤45 years of age and in catch-up campaigns in children ≤15 years of age in typhoid-endemic regions.
Clinical Trial NCT03933098: Immune Non-inferiority and Safety of a Vi-DT Typhoid Conjugate Vaccine
- This is a Multicenter, observer-blinded, randomized, Active controlled, Phase 3 study in healthy 6 months to 45 years aged Nepalese at the time of the first vaccine dose.
- The study objectives are:
I. Demonstrate non-inferiority of Vi-DT compared to Typbar TCV® as measured by seroconversion rates of anti-Vi IgG ELISA antibody titers, 4 weeks after single dose (pooled immunogenicity of three lots of Vi-DT)
II. Demonstrate the equivalence of immunogenicity as measured by anti-Vi IgG GMT of three lots of Vi-DT vaccine 4 weeks after single dose.
Clinical Trial NCT03600025: Cellular Immune Responses in Typhoid Fever Patients and Vaccinees (Recruiting)
- This Phase 1 clinical trial is to further understand the role of mucosal-associated invariant T cell (MAIT) and natural killer (NK) cell responses in typhoid fever or following vaccination.
- Transcriptome profiling of human immune responses to S. Typhi infection is not clearly understood.
- Establishing successful infection by S. Typhi evasion of T cell and neutrophil responses need to be investigated to better understand the correlates of protection.