Maternal RSVpreF Vaccine Effectiveness Against Respiratory Syncytial Virus in Hospitalized Infants

Abstract

Key Points Question What is the effectiveness of maternal vaccination with bivalent respiratory syncytial virus prefusion F protein–based vaccine (RSVpreF) during pregnancy against RSV-associated hospitalization among infants in Australia? Findings In this test-negative case-control study of 1012 hospitalized infants, maternal RSVpreF vaccination was associated with 78% to 81% reduction in RSV-associated hospitalization from birth through 6 months of age, with the highest vaccine effectiveness in earliest age intervals. Vaccine effectiveness was consistent across stratifications by gestational age at vaccination, vaccination to delivery time interval, and proximal administration with other vaccines during pregnancy and was demonstrated for both RSV-A and RSV-B. Meaning In Australia, where vaccination during pregnancy is occurring from 28 weeks’ gestation, RSVpreF provides substantial year-round protection against RSV-associated hospitalization in infants 6 months of age or younger.