BAKERSFIELD, Calif. -- Though experts recommend that pregnant women get the seasonal flu shot, studies have shown that only 13 percent of pregnant women actually follow this recommendation.

Because mother and baby share immunity during pregnancy, at birth, babies are temporarily protected by their mothers' immunity.

Until recently, it was unclear whether this was the case for flu vaccines. Researchers from Yale University found that getting vaccinated while pregnant was 88 percent effective at preventing flu in the baby during its first 6 months of life.

Currently, it is difficult to protect newborns from the flu because vaccines, either for seasonal or H1N1 flu, are not approved for infants younger than 6 months, though these early months are the time when babies are most likely to be hospitalized for flu-related complications.

But these findings suggested that flu shots for pregnant women can protect young infants from potentially lethal flu.