Missed vaccines in pregnant women: A contributing factor to pertussis outbreak in newborns and infants

Background: Pertussis has re-emerged as a significant public health concern in Europe and an outbreak has been recently described in Italian newborns and infants. Maternal vaccination is a crucial strategy for protecting infants too young to be vaccinated. At present, data on vaccination coverage among pregnant women in Italy are lacking. Methods: A national online survey targeting Italian mothers with infants <12 months of age was conducted in May–July 2024 to assess pertussis vaccination coverage during pregnancy, as well as knowledge, attitude, and barriers to vaccination. Results: Among 404 participants, 37.4 % had not received the pertussis vaccine during pregnancy, due to misinformation (59.6 %), concerns about safety (15.2 %), and prior vaccination or infection (7.3 %). Additionally, 9.4 % of participants were unaware that pertussis is preventable by vaccination, 7.9 % did not consider pertussis a serious disease. Vaccination coverage varied significantly by region, with a north-south gradient (72.6 % in the north vs. 49.7 % in the south, p < 0.001). Regions with lower maternal vaccination rate exhibited a higher number of hospitalized infants for pertussis. Factors influencing missed maternal vaccinations were: being from southern Italy (aOR 8.339, 95 % CI 2.813–24.716), misinformation about pertussis vaccination during pregnancy (aOR 18.564, 95 % CI 4.620–74.587), and fear of side effects (aOR 2.560, 95 % CI 1.044–6.277). Conclusion: Maternal pertussis vaccination coverage in Italy is suboptimal, contributing to the recent outbreak. Misinformation, safety concerns, and regional disparities are significant barriers. Targeted educational interventions for general population and healthcare providers, along with on-site vaccination opportunities, are essential to improve vaccination coverage and to prevent future outbreaks.