By Sue Hubbard, M.D.
I just had my flu vaccine! Guess what - my arm didn't even hurt this year. I have also been reminding all of the pregnant mothers that I see to get their flu vaccines. The current recommendation is that pregnant women receive influenza vaccine as soon as possible beginning after their 28th week of pregnancy (third trimester).
When a pregnant woman receives her flu vaccine, she is not only protecting herself but also her baby. Infants cannot receive a flu vaccine until they are 6 months old; and for babies born during the fall and winter season, that means they will not be vaccinated until the following year. But when a mother has received a flu vaccine the infant is also getting protection via antibody that the mother passes to her baby across the placenta.
In a 2014 study, the authors reported that "immunization of pregnant women with trivalent inactivated influenza vaccine (IIV3) was safe, immunogenic, and partially protected the women with a vaccine efficacy of 50 percent and their infants with a vaccine efficacy of 49 percent against laboratory-confirmed influenza illness during a six-month follow-up post-delivery." In other words, the infants in the study had just as much protection as the mother.
In a more recent study, the authors now looked at how long the immunity lasted in the infants born to the flu vaccinated mothers. Surprisingly, the immunity was not as long lived as had been thought. The infants involved in the study were born an average of 81 days after their mothers were vaccinated with flu vaccine, and were monitored for influenza infection for about 172 days after birth.
Infants born to mothers who had a longer interval between vaccination and delivery had higher antibody titers. The infants' antibody levels did drop off after birth, and by 8 weeks of age the babies did not have significant antibody. Ideally, in order for babies to have better protection a mother would be vaccinated even earlier in her pregnancy, and studies are being done to look at this possibility.
Infants are especially susceptible to influenza and have a higher rate of complications as well as hospitalizations. While the current recommendations for vaccinating pregnant women may not confer as much immunity to the newborn as was previously thought, there is very high protection for the first eight weeks after birth. Any protection is preferable to none!
Get your flu vaccine; and if you are pregnant ask your doctor to give it to you as soon as you are in your 28th week. The longer the baby is getting placental antibody the better!
Dr. Sue Hubbard is an award-winning pediatrician, medical editor and media host. "The Kid's Doctor" TV feature can be seen on more than 90 stations across the U.S. Submit questions at http://www.kidsdr.com. The Kid's Doctor e-book, "Tattoos to Texting: Parenting Today's Teen," is now available from Amazon and other e-book vendors.
This was printed in the October 30, 2016 - November 12, 2016