Typhoid vaccine prequalified

3 January 2018 - WHO has prequalified the first conjugate vaccine to prevent typhoid fever called Typbar-TCV® developed by Indian pharmaceutical company Bharat Biotech.

The vaccine has long-lasting immunity, requires only one dose and can be given to children as young as 6 months through routine childhood immunization programmes. Other Typhoid vaccines are recommended for children over 2 years of age.

Prequalification by WHO means that the vaccine meets standards of quality, safety and efficacy, thus making it eligible for procurement by United Nations agencies, such as the United Nations Children’s Fund.

A conjugate vaccine is one that is composed of a polysaccharide antigen that is fused to a carrier molecule.

In October 2017, the Strategic Advisory Group of Experts (SAGE) on immunization, which advises WHO, recommended typhoid conjugate vaccine for routine use in children over six months of age in typhoid endemic countries.

SAGE also called for the introduction of typhoid conjugate vaccine to be prioritized 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 thus help slow the increase in antibiotic resistance in Salmonella Typhi.

Shortly after SAGE’s recommendation, Gavi’s board approved US$ 85 million in funding for typhoid conjugate vaccines starting in 2019.

Prequalification is a crucial step for making the vaccines available in low-income countries, while in countries that Gavi does not support, prequalification can help expedite licensure.

Global estimates of the typhoid burden range between 11 and 20 million cases and between about 128 000 and 161 000 typhoid deaths annually.