Maternal Immunization Earlier in Pregnancy Maximizes Antibody Transfer and Expected Infant Seropositivity Against Pertussis

摘要: Background. Maternal immunization against pertussis is currently recommended after the 26th gestational week (GW). Data on optimal timing of maternal are inconsistent. Methods. We conducted a prospective observational noninferiority study comparing influence second-trimester (GW 13–25) vs third-trimester (≥GW 26) tetanus-diphtheria-acellular (Tdap) in pregnant women who delivered at term. Geometric mean concentrations (GMCs) cord blood antibodies to recombinant toxin (PT) and filamentous hemagglutinin (FHA) were assessed by enzyme-linked immunosorbent assay. The primary endpoint GMCs expected infant seropositivity rates, defined birth anti-PT >30 assay units (EU)/mL confer until 3 months age. Results. We included 335 (mean age, 31.0 ± 5.1 years; 39.3 1.3 GW) previously immunized with Tdap second (n = 122) or third 213) trimester. Anti-PT anti-FHA higher following second- (PT: 57.1 EU/mL [95% confidence interval {CI}, 47.8–68.2] 31.1 CI, 25.7–37.7], P < .001; FHA: 284.4 241.3–335.2] 140.2 115.3–170.3], .001). adjusted GMC ratios differed significantly 1.9 1.4–2.5]; 2.2 1.7–3.0], Expected rates reached 80% 55% (adjusted odds ratio, 3.7 2.1–6.5], .001). Conclusions. Early increased neonatal antibodies. Recommending from trimester onward would widen opportunity window could improve seroprotection.