TCVs are innovative products that have longer-lasting immunity than older vaccines, require fewer doses, and can be given to young children through routine childhood immunisation programmes
At the end of December 2017, WHO prequalified the first conjugate vaccine for typhoid, Bharat Biotech’s Typbar-TCV. Typhoid conjugate vaccines (TCVs) are innovative products that have longer-lasting immunity than older vaccines, require fewer doses, and can be given to young children through routine childhood immunisation programmes. The fact that the vaccine has been prequalified by WHO means that it meets acceptable standards of quality, safety and efficacy. This makes the vaccine eligible for procurement by UN agencies, such as UNICEF, and Gavi, the Vaccine Alliance.
In October 2017, the Strategic Advisory Group of Experts (SAGE) on immunisation, which advises WHO, recommended TCV for routine use in children over six months of age in typhoid endemic countries. SAGE also called for the introduction of TCV to be prioritised for countries with the highest burden of typhoid disease or of antibiotic resistance to Salmonella Typhi, the bacterium that causes the disease. Use of the vaccine should also help to curb the frequent use of antibiotics for treatment of presumed typhoid fever, and thereby help to slow the alarming increase in antibiotic resistance in Salmonella Typhi.
Shortly after SAGE’s recommendation, Gavi Board approved $85 million in funding for TCVs starting in 2019. Prequalification is therefore a crucial next step needed to make TCVs available to low-income countries where they are needed most. And even in non-Gavi-supported countries, prequalification can help expedite licensure.