The best way to disrupt the spread of influenza is immunization for everyone — even the healthiest people — beginning at 6 months of age.
But what about the very young — infants under 6 months for whom no flu vaccines are licensed? The best way to protect them from influenza is by vaccinating their mothers while they’re pregnant.
In a randomized Bangladesh study, pregnant mothers who received flu vaccine reported 36 percent less flu-like illness than those who hadn’t received the vaccine. But more notable, their babies, from birth to 6 months, had 63 percent fewer cases of lab-proven influenza.
Studies in America are just as convincing. A 2009 Yale School of Medicine case control study found that “vaccinating mothers during pregnancy was 80 percent effective in preventing hospitalization due to influenza in their infants during the first year of life and 89 percent effective in preventing hospitalization in infants under six months of age.” A recent case control trial of flu vaccine in mothers in the Apache and Navajo reservations showed a 41 percent reduction of lab-proven flu in the infants.
Reports from the Vaccine Adverse Event Reporting System, based at the CDC and FDA, which collects information about adverse events, suggests that the vaccine is safe in pregnant women. A recent report of 20 years of U.S. data shows that there were no increased pregnancy complications or poor fetal outcomes after the administration of influenza vaccine in pregnancy. In summary: adverse events are very rare with flu vaccine administered during pregnancy.
Flu vaccine has been around for more than 50 years. We’ve had a lot of experience using it, and we’ve improved it with each passing decade.
Universal immunization is still a relatively new concept for the United States. Vaccinating children up to age 18 was first recommended in 2008. We still wrestle with having enough vaccine and a large enough system to deliver it. No doubt we need to work out some kinks. But it’s a strategy worth fighting for.
Mark C. Steinhoff, MD, is the Director of the Global Health Center at Cincinnati Children’s. Dr. Steinhoff works with the Global Health Center to focus on advocacy, education, scholarship, research, and leadership training for Cincinnati Children’s and the University of Cincinnati.
