Aim: To evaluate a low cost Indian recombinant hepatitis B vaccine GeneVac-B for its immunogenicity and safety in comparison to Engerix B and Shanvac B vaccine in high risk newborn infants born to hepatitis B surface antigen (HBsAg) positive mothers.
Methods: A total of 158 infants were enrolled in the study. Fifty eight infants were enrolled in the GeneVac-B group while 50 each were included for Engerix B and Shanvac B groups. A three-dose regimen of vaccination; at birth (within 24 h of birth), 1st mo and 6 mo. were adopted with 10 mug dosage administered uniformly in all the three groups. Clinical and immunological parameters were assessed for safety and immunogenicity of the vaccines, in all the enrolled infants.
Results: Successful follow up until seven months of age was achieved in 83% (48/58) for GeneVac-B, 76% (38/50) and 64% (32/50) for Engerix B and Shanvac B groups respectively. 100% seroconversion and seroprotection was achieved in all the three groups of infants. The geometric mean titers of anti-HBs one month after the completion of three dose of vaccination were 90.5, 80.9 and 72.5 mIU/mL in GeneVac-B, Engerix B and Shanvac B vaccine group respectively. Furthermore the level of anti-HBs increases with age of babies who were born to HBsAg positive mothers. The GMT values of anti-HBs were 226.7, 193.9 and 173.6 mIU/mL respectively in GeneVac-B, Engerix B and Shanvac B groups one year after the completion of the three doses of vaccine. No systemic reactions were reported in infants during the entire vaccination process of GeneVac-B and the other two vaccines. Clinical safety parameters remained within the normal limits throughout the study period.
Conclusion: The study concludes that there is no significant difference between the three recombinant hepatitis B vaccines. Administration of these vaccines within 24 h of birth to babies, born to HBsAg positive mothers will reduce the incidence of HBV infection.