Context: Indian drug Typbar TCV Vaccine is prequalified by WHO
- Typhoid fever is a systemic infection caused by Salmonella Typhi, usually through ingestion of contaminated food or water.
- The acute illness is characterized by prolonged fever, headache, nausea, loss of appetite, and constipation or sometimes diarrhoea
- Three typhoid vaccines are currently recommended by WHO for control of endemic and epidemic typhoid fever:
- an injectable typhoid conjugate vaccine (TCV), consisting of Vi polysaccharide antigen linked to tetanus toxoid protein licensed for children from 6 months of age and adults up to 45 years of age;
- an injectable unconjugated polysaccharide vaccine based on the purified Vi antigen (known as Vi-PS vaccine) for persons aged two years and above; and
- an oral live attenuated Ty21a vaccine in capsule formulation for those over six years of age.
- Among the available typhoid vaccines, TCV is preferred at all ages for routine programmatic use in view of its improved immunological properties, suitability for use in younger children and expected longer duration of protection
- WHO-prequalified Indian manufactured drug Typbar TCV, showed a protective efficacy of 1 dose of TCV as 81.6%