The development of enteric fever vaccine

There is a huge global burden of enteric fever which disrupts the lives of children in settings with inadequate quality water and poor sanitation. This non-specific febrile illness affected approximately 9.3 million people in 2021, resulting in over 100,000 deaths and 8.1 million disability-adjusted life years. Accurately assessing the true burden of the diseases remains difficult due to the lack of sensitive diagnostic tests, adequate laboratory facilities, and robust surveillance systems in endemic regions. As a result, current global estimates may underrepresent the actual disease burden.

The first typhoid conjugate vaccine (TCV) (Typbar® TCV, Bharat Biotech International Limited) received WHO prequalification in 2017, based on field safety and immunogenicity data and supported by findings from a controlled human infection model. Since then, the two-year vaccine efficacy has been confirmed at 79%-85% by randomised controlled trials (RCTs) in Nepal, Bangladesh, and Malawi. Over 60 million doses of typhoid conjugate vaccines have been rolled out in the past 5 years. This talk will focus on results from a cluster randomise trial in the Bangladesh to discuss about the development of enteric fever vaccines.