Serological Status of Vaccine and Hepatitis B Virus Exposure Among Children Under 5 and Aged 15–17 Years in Kampala, Uganda

This study looked at how well children in Kampala, Uganda are protected against hepatitis B virus (HBV) after receiving the vaccine through the country’s national immunization program. The researchers tested blood samples from 789 children collected between May and August 2023 — 501 under 5 years old and 288 aged 15–17 — all of whom had received at least one dose of the hepatitis B vaccine. They measured several markers of infection and vaccination, including the virus itself and antibodies that indicate past exposure or vaccine‑induced protection.

Overall, only about 28% of all children had detectable protective antibodies from the vaccine. Among the younger group, 33% had these antibodies, while only 18% of adolescents did. This suggests that protection likely decreases with time after vaccination. The prevalence of active HBV infection was 1.52% overall, with a higher rate in adolescents (about 2.8%) than in the younger group (about 0.8%). Most of the infected children did not have detectable protective antibodies.

These findings indicate that a large proportion of vaccinated children may not have lasting protective immunity, especially by adolescence. The authors suggest that a booster dose of the hepatitis B vaccine for older children may be needed to improve long‑term protection.

Disclaimer: This lay summary was generated by AI and has not been approved by any of the authors yet.