Clinical experience of a tricomponent acellular pertussis vaccine combined with diphtheria and tetanus toxoids for primary vaccination in 22,505 infants

Objectives: To assess the safety and tolerability of 12 lots of SmithKline Beecham Biologicals' diphtheria-tetanus-tricomponent acellular pertussis vaccine (DTaP) in a large cohort of 22,000 vaccinees, with detailed analyses of reactivity, immunogenicity, and immune response to pertussis toxin in subsets. Methods: In a prospective, double-blind, multicenter trial in Germany, 22,505 healthy infants received three vaccinations of DTaP at age 3, 4, and 5 months. Serious adverse events were followed for 1 month after each vaccination, and neurologic events for 1 year or longer, Serum IgG antibodies were assayed before vaccination and 1 month after vaccination. Results: After 67,000 doses, 153 serious adverse events (0.23%) were reported, 8 considered possibly related, and 5 related to vaccination, including 1 hypotonic-hyporesponsive episode, Incidence rates of sudden infant death syndrome (7; 0.01%) or acute neurologic events (20; 0.030%) were no higher than expected and not considered to be related to vaccination, Redness and swelling of 20 mm or greater occurred after 44 (0.6%) and 40 (0.6%) of the 7270 doses, respectively, and high fever (>39,5 degrees C) in 6 (0.08%) subjects within 48 hours of vaccination. in the immunogenicity analysis of 580 infants, 98% responded to pertussis toxin, 96% to filamentous hemagglutinin, and 98% to pertactin, In an additional 5712 infants, the response rate to pertussis toxin was 99%. Conclusions: In a large cohort of 22,505 infants vaccinated, SmithKline Beecham Biologicals' tricomponent DTaP vaccine was shown to be safe, well-tolerated, and immunogenic for all component antigens.