Immunogenicity and reactogenicity of an inactivated hepatitis A vaccine inIndian adults

Background. In India, a possible decrease in the prevalence of and-HAV (hep atitis A virus) antibodies in adults has increased their susceptibility to HAV infection. We evaluated the immunogenicity and reactogenicity of an ina ctivated hepatitis A vaccine administered in a 3-injection protocol. Methods. Thirty-five healthy adult volunteers, seronegative for anti-HAV Ig G, were administered 720 ELISA units/ml of the inactivated hepatitis A vacc ine intramuscularly at days 0, 30 and 180, Anti-HAV IgG was determined at d ays 30, 60, 90 and 180 to assess the efficacy of the Vaccine and adverse re actions were noted to evaluate its reactogenicity. Results. The mean (SD) age of the volunteers was 33.1 (12.3) years and the man:woman ratio was 19:16, An overall seroprotection of 37.2% (13/35) was o btained at day 30, 57.1% (20/35) at day 60 and 85.7% (30/35) at day 90, By day 180, all the vaccinees (35/35; 100%) achieved protective seroconversion . The vaccine in general was well tolerated and no serious side-effects wer e observed. Only 8.6% (3/35) of subjects developed minor self-resolving adv erse reactions such as local pain, erythema and/or low-grade fever. Conclusions. The inactivated hepatitis A vaccine in a three-infection proto col (0, 30 and 120 days) is safe, well tolerated and highly immunogenic in adult Indian subjects.