Assessment of immune response and safety of two recombinant hepatitis B vaccines in healthy infants in India

Abstract

Hepatitis B infection and its sequel continue to be a worldwide health problem, especially in the developing countries. The pool of chronic carriers of hepatitis B virus is built up in childhood and is then maintained in older children and adults. Therefore, it is important to give protection during infancy. Effective vaccines to prevent hepatitis B infection are available. This study was undertaken to evaluate the immune response and reactogenicity of two recombinant hepatitis B vaccines available in Indian market, in normal healthy infants. Infants of 6-8 weeks of age were screened for eligibility criteria. All the eligible subjects had negative baseline serum HBsAg and anti-HBs. The subjects received three doses of 10 µg of Gene Vac-B or Engerix-B at 6, 10 and 14 weeks of age. GeneVac-B is an indigenously manufactured vaccine, while Engerix-B is an imported vaccine. The vaccinees were assessed for immune response and safety parameters. The anti-HBs antibody titer was obtained 1 month after 3 rd dose of vaccine and was considered seroconverted if more than 1 mIU/ml, and seroprotective if more than 10 mIU/ml. Total of 126 subjects were considered for analysis. One month after 3 rd dose, seroconversion was 100% for both the vaccines and seroprotection was 94.36% for Gene Vac-B, and 92.72% for Engerix B. The GMT of anti-HBs antibodies were 149.47 mIU/ml for Gene Vac-B and 153.28 mIU/ml for Engerix B. Four cases of incessant cry were observed during the study period. The indigenous vaccine, Gene Vac-B and the imported vaccine, Engerix-B showed high immunogenicity and safety profile in Indian infant population. Both vaccines were comparable.