Safety and health-related quality of life following maternal respiratory syncytial virus (RSV) and diphtheria–tetanus–acellular pertussis (DTaP) vaccinations

Maternal respiratory syncytial virus (RSV) and pertussis vaccinations are recommended in some countries. While Tdap is widely used in pregnant women, DTaP is the approved pertussis vaccine in Japan. This study aimed to evaluate the safety of maternal RSV and DTaP vaccination, including reactogenicity and pregnancy and neonatal outcomes. This observational study included pregnant women vaccinated with RSV or DTaP. Reactogenicity and health-related quality of life were assessed daily. Pregnancy and neonatal outcomes, including preterm delivery, hypertensive disorder of pregnancy (HDP), cesarean section, low birth weight and NICU admission, were compared with an unvaccinated historical cohort. A total of 252 RSV-vaccinated and 159 DTaP-vaccinated pregnant women were included. Twin pregnancy occurred in 13.9%, 7.4%, and 6.6% of the RSV-vaccinated, DTaP-vaccinated, and unvaccinated cohorts. Grade 1-2 local adverse events occurred in 108 (46.1%) RSV-vaccinated and 102 (75.0%) DTaP-vaccinated women (<i>p</i> < .001), whereas grade 1-2 systemic adverse events occurred in 133 (56.8%) and 61 (44.8%) women (<i>p</i> = .031), respectively. None of the adjusted odds ratios for preterm delivery, HDP, cesarean section, low birth weight, or NICU admission were increased in the RSV-vaccinated and DTaP-vaccinated groups, compared with the unvaccinated group. Maternal RSV and DTaP vaccinations were well tolerated and not associated with increased risks of adverse pregnancy or neonatal outcomes. These findings support broader implementation of maternal vaccination in populations with high twin pregnancy rates.