Maternal Vaccination and Infant Influenza and Pertussis

BACKGROUND AND OBJECTIVES Infant influenza and pertussis disease causes considerable morbidity and mortality worldwide. We examined the effectiveness of maternal influenza and pertussis vaccines in preventing these diseases in infants. METHODS This inception cohort study comprised women whose pregnancies ended between September 1, 2015, and December 31, 2017, in Victoria, Australia. Maternal vaccination status was sourced from the Victorian Perinatal Data Collection and linked to 5 data sets to ascertain infant outcomes and vaccination. The primary outcome of interest was laboratory-confirmed influenza or pertussis disease in infants aged RESULTS Among 186 962 pregnant women, 85 830 (45.9%) and 128 060 (68.5%) were vaccinated against influenza and pertussis, respectively. There were 175 and 51 infants with laboratory-confirmed influenza and pertussis disease, respectively. Influenza VE was 56.1% (95% CI, 23.3% to 74.9%) for infants aged CONCLUSIONS Our study provides evidence of the direct effectiveness of maternal influenza and pertussis vaccination in preventing these diseases in infants aged