Immunogenicity and safety of an indigenously manufactured reconstituted pentavalent (DTwP-HBV+Hib) vaccine in comparison with a foreign competitor following primary and booster immunization in Indian children.

ABSTRACT

OBJECTIVE: An open label, controlled clinical study was conducted in Indian infants aged 6-14 weeks to compare the immunogenicity and safety of a reconstituted pentavalent vaccine (DTwP-HBV+Hib) of Serum Institute of India Ltd (SIIL) with TritanrixHB+Hiberix vaccine of Glaxo Smithkline (GSK). METHODS: Eligible infants were randomized to receive three doses of the study / comparator vaccine. The vaccines were reconstituted prior to administration, by mixing DTwP-HBV (liquid) with the Hib (lyophilized) vaccine. IgG antibody titres were assessed by ELISA at baseline and after one month following the 3-dose primary immunization schedule. Safety was evaluated after each dose. Further, safety and immunogenicity was also evaluated following a booster dose in the same cohort of children (aged between 15-24 months). SETTING: Tertiary-care hospitals in India Important outcome measures: Immunogenicity and safety following a 3-dose primary vaccination series and a booster vaccination. RESULTS: Post-primary immunization, 100% seroprotection was noted for Diphtheria, Tetanus, Hepatitis B and PRP-Hib components in both the vaccine groups. For pertussis, response was 96.1% in SIIL and 95.4% in GSK group. The overall safety profile as well as persistence of antibodies against all vaccine components up to the time of booster immunization was comparable between the SIIL and GSK groups. A marked rise of all antibody concentrations indicated effective priming. The booster dose was safe, well tolerated with a significant increase in antibody concentrations of all the vaccine antigens in both the groups. CONCLUSION: DTwP-HBV+Hib vaccine of SIIL was found to be safe and immunogenic. This Indian vaccine compared well with the licensed vaccine and is a cost-effective alternative for incorporating into the immunization schedule of various countries so as to control worldwide Hepatitis B and Hib infections.