Daily Dose: Efficacy of Maternal RSV Vaccine

Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.


On November 2, 2022, we reviewed top-line data from a global phase 3 clinical trial investigating the efficacy of Pfizer's investigational bivalent RSV prefusion vaccine candidate, RSVpreF or PF-06928316, to protect infants after birth when the shot is given to pregnant women.

The study

Data from the MATISSE (MATernal Immunization Study for Safety and Efficacy) trial showed that RSVpreF efficacy was 81.8% against severe medically attended lower respiratory tract illness (MA-LRTI) in infants through the first 90 days of life and it remained high through the first 6 months of follow-up. Also, results showed an efficacy of 57.1% for nonsevere MA-LRTI among infants from birth through the first 90 days of life, which declined to 51.3% over the follow-up period. No safety concerns were reported for either vaccinated mothers or their newborns.

Clinical implications

“A maternal vaccine with high efficacy that can help protect infants from birth could substantially reduce the burden of severe RSV among newborns through six months of age, and, if approved by regulatory authorities, will likely have a significant impact on disease in the U.S. and globally.”

Click here for the full study review.