Flu Shots for Pregnant Women May Protect Infants
Pregnant women who get their flu shots are not only protecting themselves against flu-related complications—they may also be protecting their infants after they are born. That is the finding of new research reported in the American Journal of Obstetrics & Gynecology.
Pregnant moms pass on protection to infants
Influenza vaccination is recommended for all children ages 6 months to 18 years because this age group is associated with a large number of hospitalizations and outpatient visits. However, the highest number of pediatric hospitalizations for flu is among infants younger than 6 months, the age group for which there are no licensed flu vaccines.
One way to help protect these infants is to recommend that everyone who has close contact with infants be vaccinated. Now new research indicates that one other path of protection may lie with pregnant women who get their flu shots.
The study’s investigators, led by Katherine Poehling, MD, MPH, of Wake Forest University, evaluated data from seven consecutive flu seasons from before the H1N1 pandemic. The data was collected by the Centers for Disease Control and Prevention-funded New Vaccine Surveillance Network for flu seasons from November through April during 2002 to 2009.
A total of 1,510 infants who were hospitalized with respiratory symptoms, fever, or both during the first six months of their lives were analyzed. Overall, 151 (10%) of the babies had confirmed influenza and 294 (19%) of the mothers had been vaccinated against flu during pregnancy. Eighteen (12%) of mothers who had infants with flu and 276 (20%) of mothers of infants negative for flu were vaccinated.
Overall, the researchers found that infants younger than 6 months who were born to women vaccinated for flu during pregnancy were 45 to 48 percent less likely to be hospitalized with flu than those born to unvaccinated women. Poehling noted that “our results support the current influenza vaccination recommendation for pregnant women.”
Another possible benefit for infants born to women vaccinated for flu was reported in the same issue of the journal. Shelly McNeill, MD, of the Canadian Center for Vaccinology in Halifax, Nova Scotia, and her colleagues, found that flu vaccination during pregnancy may avoid impaired fetal growth in infants born to women who suffer a serious respiratory infection while pregnant.
Generally, the findings of these two studies support the recommendation of flu shots for pregnant women, not only for their own health, but also to protect their infants.
McNeil S et al. American Journal of Obstetrics & Gynecology 2011; doi: 10.1016/j.ajog.2011.04.032
Poehling K et al. American Journal of Obstetrics & Gynecology 2011: doi:10.1016/j.ajog.2011.02.042