Immune Response of Ghanaian Children to the Hepatitis B Antigen in the Pentavalent (DPT-HepB-Hib) Vaccine in Accra

Abstract

Background: There is no data on the hepatitis B surface antibody responses (anti- HBs) in children after the introduction of the pentavalent (DPT-HepB-Hib) vaccine in Ghana. Method: Sera from 424 children aged 5 months to 32 months were tested for anti- HBs using an ELISA, (Antisurase B-96, General Biological Corp., Taiwan). A cross- section of those positive for anti-HBs were tested for hepatitis B core antibody (HBcAb) using Foresight® ELISA (Acon laboratories Inc., USA), and those negative for anti-HBs were tested for hepatitis B surface antigen (HBsAg) using Surase B-96 ELISA (General Biological Corp., Taiwan) and Wondfo ® rapid screening test (Guangzhou Wondfo Biotech Ltd., China). The primary outcomes of the study were the ability of children to develop a minimum of 10 and 100mIU /ml of anti-HBs. A questionnaire was used to obtain data to determine the correlates for anti-HBs responses. Results: Of the 424 children, 358 (84.4%) developed anti-HBs while 340 (80.2%) and 205 (48.3%) developed ≥10 and ≥100 mIU/ml anti-HBs titres respectively. A total of 308 (87.0%) of the 354 out of 358 who developed some level of anti-HBs were non-reactive to the test for anti-HBc. Of the 66 who were anti-HBs negative, 3 (4.6%) were HBsAg positive. The use of vaccines from different manufacturers for one individual and the ages of the children, had significant effect on anti-HBs titre (p <0.050). The most significant differences in correlates were seen when a minimum anti-HBs protection of ≥100 mIU/ml was assumed. Conclusion: There is a need to consider giving a booster hepatitis B vaccine at 9 months and to adhere to protocols for hepatitis B virus prophylaxis in exposed neonates.