CDC Research

Vaccination Gaps Leave Pregnant Moms, Infants Unprotected

October 16, 2019 03:41 pm News Staff

Despite having been the standard of care for years, about 65% of mothers recently surveyed reported they had not received the seasonal influenza and tetanus, diphtheria and acellular pertussis vaccines before or during their pregnancy.

[young pregnant woman receiving vaccination]

That's according to a CDC Morbidity and Mortality Weekly Report(www.cdc.gov) posted online Oct. 8 as an MMWR Early Release along with an accompanying Vital Signs(www.cdc.gov) report.

Because newborns who contract influenza or pertussis are at high risk for hospitalization and death, the CDC recommends that all pregnant women receive flu vaccine at any point during pregnancy and that Tdap vaccine be administered early in the third trimester of pregnancy as part of routine prenatal care.

The flu vaccine, in particular, also benefits the mother, given that pregnant women have a more than twofold risk for hospitalization compared with nonpregnant women if they contract influenza.

Story Highlights
  • According to recent research from the CDC, about 65% of mothers surveyed reported they had not received the seasonal influenza and tetanus, diphtheria and acellular pertussis vaccines before or during their pregnancy.
  • The agency recommends that all pregnant women receive flu vaccine at any time during pregnancy and pertussis vaccine early in their third trimester as part of routine prenatal care.
  • Women whose health care professionals offered or referred them for vaccination had the highest vaccination rates.

"I want to reinforce that all expectant mothers should be up to date with recommended vaccinations as part of their routine prenatal care," said CDC Director Robert Redfield, M.D., in a press release.(www.cdc.gov) "CDC strongly recommends that health care providers speak with moms-to-be about the benefits of safe Tdap and flu vaccination for their health and the well-being of their babies."

Report Details

For the MMWR report, the CDC analyzed data from the Influenza Hospitalization Surveillance Network and the Influenza-Associated Pediatric Mortality Surveillance System for the 2010-11 through 2017-18 influenza seasons to determine the proportion of influenza-associated hospitalizations among females ages 15-44 that occurred in pregnant women, as well as the number of influenza-associated hospitalizations per 100,000 population and influenza-associated mortality in infants 6 months or younger.

In addition, researchers analyzed data from the National Notifiable Diseases Surveillance System for 2010-17 to obtain pertussis case counts, hospitalization proportion (calculated for the 64% of infants with known outcome) and mortality in infants 2 months or younger.

Infants younger than 6 months have the highest incidence of influenza-associated hospitalizations and highest risk of influenza-related death among children overall, the CDC said. Vaccinating pregnant women reduces the risk of flu-related hospitalization in these infants by an average of 72%.

Pertussis also can be deadly for young infants, especially before they get their first vaccination against the disease at age 2 months. Two-thirds of infants younger than this age who contract pertussis require hospitalization, and about 70% of deaths related to pertussis occur in this group, according to the MMWR.

"By getting Tdap vaccine during the third trimester of pregnancy, mothers build high levels of antibodies that transfer to the fetus and continue to protect the baby after birth, preventing more than three in four cases (78%) of whooping cough in babies under 2 months old," the CDC release said.

How Family Physicians Can Help

In addition to reviewing data from the sources noted, the CDC surveyed nearly 2,100 women ages 18 to 49 who were pregnant any time between August 2018 and April 2019 to ask about their vaccination status with regard to these two vaccines. Among the survey findings:

  • 54% of pregnant women reported receiving flu vaccine before or during pregnancy.
  • 55% of women reported receiving Tdap during pregnancy.
  • Women whose health care professionals offered or referred them for vaccination had the highest vaccination rates.

Overall, 73.3% of survey respondents reported being offered vaccination or a referral for influenza vaccine, and 76% of respondents reported the same for Tdap. Among those who received an offer or referral, 65.7% received influenza vaccine, and 70.5% received Tdap.

Black women and unmarried women were less likely to report being offered or referred for either vaccine, the MMWR said. Offers of or referrals for flu vaccination were reported less often by women with a college degree or less education, uninsured women, women who lived in the South or who lived below the federal poverty line, those without other high-risk medical conditions, and those with 10 or fewer health care visits since July 2018. Offers of or referrals for Tdap vaccination were less frequently reported among women ages 35-49, women who worked, and those who had either the highest or lowest education levels.

Among women who did report offers of or referrals for vaccination, receipt of either vaccine varied by demographic characteristics, with some of the largest gaps in coverage (more than 20 percentage points) seen between black and non-Hispanic white women.

Influenza vaccination coverage was 28 percentage points lower among uninsured than privately insured women; the sample size was inadequate to analyze coverage for Tdap, the CDC said.

As for why women said they did not receive influenza vaccination, 17.6% said they believed it to be ineffective. For Tdap, the most commonly cited reason for nonvaccination -- reported by 37.9% of women -- was not knowing that the vaccine should be administered during every pregnancy, according to the MMWR.

Interestingly, for both vaccines, the second most common reason for nonvaccination was concern about safety risks to their infant (influenza 15.9%; Tdap 17.1%).

To boost influenza and pertussis vaccination in this patient population, the CDC recommends that family physicians

  • discuss the benefits of vaccination with pregnant women early and often,
  • strongly recommend flu and Tdap vaccines,
  • offer flu and Tdap vaccines to pregnant women or provide referrals for this service, and
  • reinforce that vaccination is the best way to protect infants from influenza and pertussis.

Related AAFP News Coverage
CDC Launches #HowIRecommend Vaccination Video Series
(8/13/2019)

Tdap Vaccine During Pregnancy Reduces Newborn Pertussis
(10/10/2017)

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