Nearly two-thirds of pregnant women have not been vaccinated against flu this season, leaving their infants vulnerable to serious illness, according to federal health officials.
The findings come as flu activity starts to rise, the Centers for Disease Control and Prevention (CDC) said Thursday.
The CDC and the Academy recommend all people 6 months and older be vaccinated against flu.
Young children, pregnant women and the elderly are especially vulnerable to flu complications. As of early November, 39% of people in the U.S. had been vaccinated, according to the CDC. That includes 49% of children ages 6 months to 4 years, 39% of children ages 5-12 years and 30% of teenagers. Roughly 68% of health care providers have been vaccinated this season, including 83% of physicians.
Just 36% of pregnant women have been vaccinated, despite recommendations from the CDC, Academy and American College of Obstetricians and Gynecologists. Pregnant women can be vaccinated during any trimester and can transfer antibodies to their infants, protecting them for up to six months.
Influenza A (H3N2) viruses have been most common this season, according to a new CDC article in the Morbidity and Mortality Weekly Report. As of Nov. 25, there had been five pediatric deaths.
Most of the viruses in the U.S. this season have been antigenically or genetically similar to cell-grown reference viruses representing vaccine viruses, but some are less similar to egg-adapted viruses used for production of the majority of U.S. influenza vaccines, according to the CDC.
A recent New England Journal of Medicine article from the National Institute of Allergy and Infectious Diseases and World Health Organization calling for a universal flu vaccine noted Australia has had record-high numbers of flu cases and an estimated 10% vaccine effectiveness against influenza A (H3N2). They said the U.S. may see similar trends.
CDC officials say they believe last year’s effectiveness estimates may be a better predictor because the H3N2 viruses circulating are similar, as are the vaccine components. Effectiveness against H3N2 last season was 32%.
