Pregnant women who get flu shots may be protecting their newborns

THE QUESTION: Among children, only those 6 months and older are given an influenza vaccination. Might younger infants glean some protection if their mothers were vaccinated while pregnant?

THIS STUDY analyzed data on 1,510 babies, 6 months or younger, who were hospitalized with a fever, respiratory symptoms or both during seven flu seasons before the H1N1 pandemic. Among their mothers, 294 had gotten a flu shot while pregnant. Lab tests confirmed that 151 of the infants had contracted the flu. About 12 percent of them had mothers who had been vaccinated for influenza, compared with 20 percent with mothers who had not been vaccinated.

WHO MAY BE AFFECTED? Infants up to 6 months old, who have a higher risk for complications from the flu than do older children. However, the flu vaccine has not been approved for use in infants younger than 6 months. To protect these infants, health experts urge that all family members and caregivers get flu shots. Although pregnant women are urged to get a flu shot, U.S. data show that only half or fewer who are pregnant during a flu season have been vaccinated.

CAVEATS: The study did not include data on infants who had flulike symptoms but were not hospitalized. Three of the study’s authors had received funding from companies that make flu vaccines.

FIND THIS STUDY: June issue of the American Journal of Obstetrics & Gynecology (

LEARN MORE ABOUT children and the flu at (click on information for parents) and (enter “Parents” site).

Linda Searing

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.