Immunogenicity, transplacental transfer of pertussis antibodies and safety following pertussis immunization during pregnancy: Evidence from a randomized, placebo-controlled trial
Abstrakt
Background: Pertussis immunization during pregnancy is recommended in many countries. Data from large randomized controlled trials are needed to assess the immunogenicity, reactogenicity and safety of this approach.
Methods: This phase IV, observer-blind, randomized, placebo-controlled, multicenter trial assessed immunogenicity, transplacental transfer of maternal pertussis antibodies, reactogenicity and safety of a reduced-antigen-content diphtheria-tetanus-three-component acellular pertussis vaccine (Tdap) during pregnancy. Women received Tdap or placebo at 27-36 weeks' gestation with crossover = 1.5.
Solicited and unsolicited adverse events (AEs) and pregnancy-I neonate-related AEs of interest were recorded. Results: 687 pregnant women were vaccinated (Tdap: N = 341 control: N = 346).
Superiority of the pertussis immune response (maternally transferred pertussis antibodies in cord blood) was demonstrated by the GMC ratios (Tdap/control): 16.1 (95% CI: 13.5-19.2) for anti-filamentous hemagglutinin, 20.7 (15.9-26.9) for anti-pertactin and 8.5 (7.0-10.2) for anti-pertussis toxoid. Rates of pregnancy-/neonate-related AEs of interest, solicited general and unsolicited AEs were similar between groups.
None of the serious AEs reported throughout the study were considered related to maternal Tdap vaccination. Conclusions: Tdap vaccination during pregnancy resulted in high levels of pertussis antibodies in cord blood, was well tolerated and had an acceptable safety profile.
This supports the recommendation of Tdap vaccination during pregnancy to prevent early-infant pertussis disease.