High risk populations such as commercial sex workers and fisher folk are being prepared for future HIV vaccine trials. However before the availability of a candidate vaccine, there is a need to study the challenges of conducting such trials in these populations, in particular retention of the study cohort.

The MRC/UVRI and other partners have been supported by IAVI to conduct Simulation Vaccine studies using a known vaccine such as Hepatitis B vaccine to understand some of these challenges. The Hepatitis B Simulated Vaccine Efficacy Trial (SiVET) is an ideal opportunity for studying how the prior status of the immune system and endemic infections affect generation of immune responses after vaccination.

Vaccine efficacy in Africa might differ from that in Europe or the USA. Environmental factors and high burden of infections in Africa might skew the immune response to vaccines and new infections. Hepatitis B vaccine is one of the widely studied vaccines and correlates of protection against Hepatitis B virus infection are known, but it is not known how the immune status at the time of vaccination, including inflammatory conditions and concurrent infections, might affect the generation of protective antibody titers to anti Hepatitis B surface antigen.

Understanding the effect of the existing immune status and the role of bacterial and helminth infections, immediately before vaccination and how these affect generation of protective vaccine responses will provide important information for designing interventions and effective vaccines against several viral diseases.

STUDY OBJECTIVES

Speaking about the study, Ms. Jackie Kyosimire Lugemwa said, “the objectives of the study is to investigate the relationship between the pre-existing status of the immune system prior to vaccination (day 0), and the immune response to Hepatitis B vaccination and to characterize the effects of prevalent infections on the immune response to vaccination”.

This study is funded by IAVI, under the Investigator Initiated Research which aims to provide opportunities for career development for junior investigators, to increase the development of scientific leadership capacity at partner Clinical research sites in Africa.