Key clinical point: Maternal immunization with a novel respiratory syncytial virus (RSV) vaccine significantly reduced the risk of severe RSV lower respiratory tract infection in infancy.

Major finding: Third-trimester maternal immunization with a novel RSV vaccine subsequently reduced infants’ placebo-subtracted rate of hospitalization for RSV lower respiratory tract infection during the first 180 days of life by 40%.

Study details: This phase 3, randomized, placebo-controlled, observer-blinded trial included 4,636 women and their infants.

Disclosures: Dr. Munoz reported receiving research grants from Janssen, the National Institutes of Health, the Centers for Disease Control and Prevention, and Novavax, which sponsored the PREPARE trial, assisted by an $89 million grant from the Bill and Melinda Gates Foundation.