The American College of Obstetricians and Gynecologists (ACOG) now recommends that eligible pregnant patients receive the maternal RSV vaccine from Sept. 1 through March 1, extending the previous end date of Jan. 31. The change is part of ACOG's 2026-27 respiratory virus season immunization guidance. The gestational age window did not change: a single dose of Pfizer's Abrysvo between 32 weeks 0 days and 36 weeks 6 days of pregnancy, for patients who do not have a delivery planned within two weeks.
ACOG says the extension reflects recent RSV seasons that have run later into the spring and become more severe. Under the old calendar, a patient who reached 32 weeks in February would have fallen outside the recommended window.
