Immunogenicity of two diphtheria-tetanus-whole cell pertussis-hepatitis B vaccines in infants: a comparative trial.

AIM: Because of the high mother-to-infant transmissibility of hepatitis B (HB) infection, neonatal vaccination is necessary, but the further doses of HB vaccines can be combined with conventional diphtheria-tetanus-whole cell pertussis (DTPw) vaccines. We compared immunogenicity and reactogenicity of two tetravalent vaccines in Indian children, who after neonatal HB immunization, were vaccinated thrice with one of these vaccines.

METHODS: In this open-label randomized study, 287 infants received a dose of an Indian- (Q-Vac (TM )) or European-made (Tritanrix-HB (TM )) tetravalent vaccine at age 6, 10, and 14 weeks. The ELISA antibodies were measured prior to the first and one month after the third dose. Immunogenicity was determined by measuring the seroprotection/seropositivity rates and geometric mean titres (GMT), whereas vaccine reactogenicity was elucidated with diary cards for 7 days following each dose. The potential unsolicited events were queried throughout the whole 3-month study period.

RESULTS: Out of the 250 subjects who completed the study, 123 received the Indian and 127 the European vaccine. After 3 doses, the seroprotection/seropositivity rates were 99 % and 100% for diphtheria, 98% and 95% for tetanus, 89% and 94% for pertussis, and 100% and 100% for hepatitis B, respectively. GMT of tetanus antibodies was significantly higher with the Indian vaccine. Low-grade reactogenicity was rather similar in the two vaccine groups, the most common events being local pain, redness, swelling, fever, irritability, unusual crying, drowsiness, and non-specific gastrointestinal symptoms.

CONCLUSIONS: Since both immunogenicity and reactogenicity of the two vaccines were almost identical, the Indian vaccine poses a good alternative to the costlier competitor vaccines.