Anti-HBs Titers Following Pentavalent Immunization (DTwP- HBV-Hib) in Term Normal Weight vs Low Birthweight Infants

ABSTRACT

Objective: To compare anti-HBs titers between term low birthweight (1800-2499 g) infants and normal birthweight infants, 6weeks after last dose of primary immunization with pentavalentvaccine, and to study adverse events following immunization(AEFI) with pentavalent vaccine.Design: Cohort study.Setting: Tertiary-care hospital predominantly catering to urbanpoor population of East Delhi.Participants: 265 low birthweight (1800-2499 g) and 265 normalbirthweight (2500-4000 g) infants. Monovalent Hepatitis B vaccinewas administered within 24 hours of birth followed by three primarydoses of pentavalent vaccine at 6, 10 and 14 weeks. Anti-HBstiters were estimated after 6 weeks of third dose of pentavalentvaccine. Adverse events following immunization (AEFI) monthwere observed for a month after each dose of pentavalent vaccine.Main outcome measures: Anti HBs antibody titers after 6 weeksof primary immunization, and AEFI.Result: 443 (83.5%) infants (225 low birthweight and 218 normalbirthweight infants) completed the follow-up. Seroprotectionagainst hepatitis B virus was achieved in both groups afterpentavalent vaccine administration. Anti HBs GMTs in lowbirthweight infants (194.8 mIU/mL) and normal birthweight infants(204.2 mIU/mL) were comparable (P = 0.17). No serious adverseevents were observed in either group.Conclusion: Three primary doses of pentavalent vaccineadministered along with zero dose of Hepatitis B vaccine at birthprovide good seroprotection. The vaccine appears to be safe inboth low birth weight and normal birthweight infants born at term.