Half of Women Receive Flu Vaccine During or Before Pregnancy

An internet panel survey assessing influenza vaccination and tetanus toxoid, reduced diptheria toxoid, and acellular pertussis (Tdap) coverage in pregnant women at the end of the flu season has found that only about half (49.1%) of pregnant women reported receiving influenza vaccine either before or during their pregnancy.

Among the 700 responders who had a live birth, just 54.4% reported receiving a Tdap during their pregnancy. The study, conducted by the US Centers for Disease Control and Prevention (CDC), found that pregnant women were commonly concerned about the efficacy of the flu vaccine, and lacked knowledge regarding the Tdap vaccine during pregnancy.

The results are particularly troubling for the population of expecting mothers, as agencies such as the Advisory Committee on Immunization Practices (ACIP) recommends that all women who are who might be pregnant receive the vaccine during flu season—regardless of the stage of pregnancy.

The survey, conducted from October 2017 to January 2018, focused primarily on the flu vaccination and Tdap coverage estimates during the 2017-18 flu season. It included women aged 18-49 years old who had reported being pregnant at any time since August 1, 2017. The total participant count was 2236 women, with data weighed to reflect age, race/ethnicity, and geographic distribution of total US population of pregnant women.

Because optimal Tdap vaccination timing is between 27-36 weeks’ gestation, investigators limited Tdcap coverage analysis to women who reported being pregnant prior to August 1, 2017, and had a live birth. Among the 815 women who fell under this category, 115 (14.1%) were excluded because they were unsure whether they had ever received the vaccination.

Along with just 49.1% receiving a flu vaccine dose since July 1, 2017 and 54.4% of eligible women receiving Tdap coverage during pregnancy, 32.8% of women with a recent live birth reported receiving both vaccines. Investigators noted that vaccination coverage among women increased with the increasing number of provider visits since July 2017—from 0 visits (18.1%) to more than 10 visits (56.8%).

Though the rate of vaccination was inconsistent across pregnant women, the survey results also showed inconsistency in healthcare provider practice. Two-thirds (66.6%) of women reported receiving a provider offer for a flu vaccination; 14.5% received a care provider recommendation but no offer, and 19.0% received no recommendation.

Vaccination rates were also more likely in women with greater levels of education (59.7% among women with a post-graduate degree vs 41.8% among women with a high school diploma or less). Women at or above the poverty level were also far more likely to be vaccinated (52.0%) than women below the poverty level (38.8%).

Among age groups, women aged 35-49 were most likely to be vaccinated (53.4%), while women aged 18-24 were the least likely (42.7%).

Still though, across all demographics, women were most likely to be vaccinated if offered coverage by a care provider, investigators noted.

“Missed opportunities to vaccinate were common, even among women with multiple health care visits,” investigators wrote. “Many pregnant women reported not receiving a provider recommendation for vaccination, which might be partly attributable to differences in perception of a provider recommendation between patients and providers.”

The CDC team concluded that vaccines rates for both influenza and Tdare are currently suboptimal, and that missed vaccination opportunities are too common. They call for the implementation of more evidence-based practices such as patient screening for recommended vaccinations at every opportunity, care provider reminders on vaccinations, and patient education on the ACIP’s vaccination recommendations that provide concrete information about maternal vaccination safety and benefits.

“Provider awareness of concern about effectiveness of the influenza vaccine, lack of knowledge about the recommendation to receive Tdap during every pregnancy, and concern about safety risks to the baby related to both vaccines can help providers address these issues with their patients through education and thus strengthen their recommendations for vaccination,” investigators wrote.

The study, "Influenza and Tdap Vaccination Coverage Among Pregnant Women — United States, April 2018," was published online in the CDC's Morbidity and Mortality Weekly Report.