Large Percentage of Pregnant Women Fail to Receive Both Tdap, Flu Vaccines

Influenza and pertussis pose a significant risk to pregnant women and infants, yet vaccination during pregnancy remains low, according to the US Centers for Diseases Control and Prevention (CDC’s) vital signs article in the Morbidity and Mortality Weekly Report.

“The biggest takeaway from the report is that the majority of pregnant women in America are not getting both of the vaccines they need during every pregnancy, leaving millions of women and babies vulnerable to influenza and pertussis, which can be prevented by safe and effective vaccines,” lead author Megan C. Lindley, MPH, deputy associate director for science in the Immunization Services Division of the CDC’s National Center for Immunization & Respiratory Diseases, told Contagion^®.

The study found that 53.7% of pregnant women reported being vaccinated for influenza before or during pregnancy, and 54.9% received the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine, while only 34.8% received both recommended vaccines.

“The reasons women do not receive both recommended vaccines during pregnancy are multifactorial and probably different for different groups of women,” Lindley told Contagion^®. “The data from our recent survey show that lack of knowledge is a significant barrier to maternal vaccination — 38% of women who did not get Tdap in their recent pregnancy reported not being aware that the vaccine was needed during every pregnancy. Continuing to work to make sure all pregnant women know what vaccines they need, and that their health care providers recommend these vaccines to pregnant patients, is vital. Providers and the public health community can also do a better job of communicating the evidence for maternal vaccination to pregnant women – for example, the primary reason women in our survey did not receive flu vaccine was belief that the vaccine is not effective. While no vaccine is perfect, we have data showing that flu vaccination not only does a good job of protecting pregnant women from influenza, but is very effective in keeping their young infants out of the hospital due to influenza infections.”

Vaccination was lower among black women, those with less than a college education, unmarried women, those living at or below the poverty line, women living in the South, those who were publicly insured, and women who didn’t report a vaccination offer or referral from a health care provider.

Vaccination was higher among women who received an offer or referral — 65.7% for influenza, 70.5% for Tdap.

“The biggest surprise we encountered is that even among pregnant women who are offered vaccination during a health care visit, nearly one-third do not get vaccinated,” Lindley told Contagion^®.

“We need to understand why a substantial proportion of women decline vaccination even when offered or given a referral,” she said. “It may be that their providers aren’t recommending the vaccines strongly, or that these women do not feel that their questions about vaccination during pregnancy have been adequately answered. It may also be that not all pregnant women understand the potentially very severe consequences of influenza or pertussis infection in their newborns. Understanding the other factors that prevent pregnant women from getting flu and Tdap vaccines will help us create better tools for health care providers to promote vaccines to their pregnant patients.”

Investigators used surveillance data to determine infections and an internet panel survey to estimate vaccination coverage.

Pregnant women accounted for 24% to 34% of influenza-associated hospitalizations among women aged 15-44 years during the 2010-11 through 2017-18 flu seasons. During the same time, 133 per 100,000 infants younger than 6 months were hospitalized with influenza, and 100 influenza-associated deaths were reported.

Meanwhile, 27,370 infants younger than 12 months were infected with pertussis between 2010 and 2017, including 9199 individuals who were younger than 2 months. The report found that 77 infants younger than 2 months died from pertussis, accounting for 69% of pertussis deaths.

“Health care providers seeing pregnant women should know that their recommendations are incredibly important,” Lindley told Contagion^®. “Not all women who receive a provider recommendation are vaccinated, but women who do not receive a recommendation for vaccination are highly unlikely to be vaccinated at all. Pregnant women trust the advice of their health care providers, and a strong, specific recommendation for flu and Tdap vaccination during pregnancy coupled with a conversation between provider and patient is an important part of routine prenatal care for every woman.”

Tdap and influenza vaccines are considered essential during pregnancy. Not only do these vaccines protect the mother, but they also provide protection for vulnerable newborns, who are not recommended to be vaccinated until 2 months for pertussis and 6 months for influenza.

Another recent survey found that while progress has been made in increasing influenza and Tdap vaccine coverage in pregnancy, significant gaps in coverage remain.