New conjugated typhoid vaccine WHO approved

Contributed by Dr Nitin Bansal

WHO announced prequalification of the first conjugate vaccine to prevent typhoid (Typbar TCV, manufactured by Bharat Biotech, India). WHO has decided that Typbar TCV was successfully assessed for quality, safety, and efficacy, and it is now approved for distribution by UN agencies. Already in use in India and Nepal in babies older than 6 months, the vaccine is to be licensed for use in infants younger than 2 years. Currently, licensed typhoid vaccines are either not immunogenic in early childhood (parenteral Vi capsular polysaccharide vaccine) or are unsuitable for administration in young children because of formulation in capsules (oral live attenuated typhoid vaccine, Ty21a). Gavi, the Vaccine Alliance, has confirmed allocation of US$85 million of funding to roll out the vaccine in south Asia, sub-Saharan Africa, and beyond between 2019 and 2020. Priced by Bharat Biotech at US$1- 1·50 per dose, other UN agencies including UNICEF are now able to procure the vaccine, in line with the WHO Strategic Advisory Group of Experts' recommendation to roll out to all infants over 6 months of age in at-risk endemic countries.

While the vaccine protects against S typhi and S paratyphi C, almost half of patients with the enteric fever syndrome in India have S paratyphi A against which the vaccine confers no protection.