From March 2nd to March 7th, a ZIG 2 and ZIG 4 research scientists traveled to Guinea to collaborate with the Institut National de Santé Publique (INSP) as part of the Vaccine Readiness in Sub-Saharan Africa (VRSA) project. The project’s current phase focuses on hepatitis B prevalence and immunity and effective vaccine coverage rates among 1- to 5-year-olds.

This work is particularly timely, as Guinea is considering introducing a hepatitis B birth dose into its immunization program. The findings from this study will provide critical evidence on hepatitis B transmission and immunity gaps, helping policymakers make informed decisions about integrating the birth dose into routine vaccination strategies.

During the current phase of the project, we are conducting the first nationwide study on hepatitis B prevalence and immunity (both vaccine-derived and infection-derived) among children aged 1–5. A key aspect of this study involves validating dried blood spot (DBS) samples against serum samples to ensure the feasibility of large-scale seroprevalence assessments.

Throughout the week, we worked closely with the INSP lab team, analyzing paired serum/DBS samples from 50 adult hepatitis B patients, as positive controls for the detection of HBV antigens and infection-induced antibodies, and 50 children who had received at least three doses of vaccine against HBV. The team’s dedication and expertise made this collaboration highly productive. We also had the opportunity to visit the laboratory facilities and were impressed by its organization and technical capacity.

Beyond the validation study, this trip also helped establish stronger ties between ZIG2, ZIG4, and the INSP’s Department of Immunology, laying the groundwork for future cooperation. The next milestone in this study will be the analysis of 1,200 samples from the main study, bringing us closer to a comprehensive understanding of hepatitis B immunity and prevalence in Guinea.