Effectiveness of dTpa vaccination during pregnancy in preventing whooping cough in infants under 3 months of age. Bizkaia, Basque Country, Spain

In response to an increase in the incidence of whooping cough in recent years, the Basque Country established a vaccination programme for pregnant women in the last trimester of the pregnancy seeking to protect young infants, a population that is at high risk of developing severe whooping cough. In the present study, based on the screening method, we assessed the effectiveness of this measure to prevent whooping cough in infants under 3 months of age. We found a vaccine effectiveness of 89% and 95% CI 72–96%. While the incidence of this disease remains high, we recommend continuing to vaccinate pregnant women in the last trimester of pregnancy.