The Effect of Pertussis Vaccination During Pregnancy on Pertussis and Diphtheria Immunity in Children at 3 and 4 Years of Age
Milja Miettinen, Mikko Lehtosalo, Alex-Mikael Barkoff, Denise Anabe, Johanna Teräsjärvi, Aapo Knuutila, Jussi Mertsola, Qiushui He, Lauri IvaskaAbstract
Pertussis vaccination during pregnancy protects young infants but blunts their antibody responses to primary immunization; the duration of this effect beyond infancy is unknown. In a clinical trial, we followed children born to tetanus-diphtheria-acellular pertussis-vaccinated (n = 47) and unvaccinated (n = 22) mothers to 4 years of age. At both 3 and 4 years, children born to Tdap-vaccinated mothers had lower anti-pertussis toxin and anti-diphtheria toxin IgG concentrations than control children, and pertussis toxin seropositivity and diphtheria seroprotection rates were low in both groups. After a preschool acellular pertussis booster at 4 years, antibody concentrations increased to comparable levels in both groups.
Clinical Trials Registration . MIFI—EudraCT 2019-001986-34; MIFI-4Y—EU Clinical Trials Information System (CTIS) EU CT 2024-510787-23-00.