October 20, 2017
2 min read

Tdap vaccinations in pregnant women increase by 50%

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The rate of pregnant women receiving a tetanus, diphtheria and pertussis vaccine jumped dramatically in numerous metropolitan areas of the United States — by more than 50% over several years — according to a recent report. The increase in immunization stems from recommendations from the Advisory Committee on Immunization Practices, researchers said.

Tdap vaccinations among pregnant women increased from less than 1% before 2009 to 54% in 2015, they wrote in an MMWR.

“These increases reflect the implementation of evolving recommendations, which currently recommend that all pregnant women be vaccinated during each pregnancy, ideally in the third trimester,” Stephen Kerr, MPH, of Boston University’s Slone Epidemiology Center, and colleagues wrote.

They assessed data on vaccinations of 5,606 infants’ mothers between 2006 and 2015. They included data from hospitals in the Philadelphia and San Diego areas, as well as statewide registries in New York and Massachusetts.

ACIP recommendations on Tdap vaccination progressed throughout the study period. In 2006, the group recommended postpartum immunization, adding that the vaccine could also be given during pregnancy.

In June 2011, the ACIP revised the timing of immunization, saying that previously unvaccinated pregnant women should receive the vaccine after 20 weeks’ gestation. And in October 2012, the group adopted its current recommendation.

The initial rate of Tdap vaccination rose to 9% in 2012, then to 28% in 2013 and 54% in 2015, Kerr and colleagues said. The proportion of women receiving Tdap in the third trimester increased from 94% in 2010 to 100% in 2015. Nearly all Tdap vaccinations — 96% — were administered in a traditional health care setting such as a primary care, obstetrics or prenatal clinic.

The proportion of women receiving Tdap in the third trimester increased from 94% in 2010 to 100% in 2015. The researchers touted the efficacy of vaccination in that trimester.

“A recent U.S. study found the Tdap vaccination during the third trimester of pregnancy was 85% more effective than postpartum vaccination at preventing pertussis in infants aged younger than 2 months,” they wrote.

They added that health care providers and patients alike can find resources at www.cdc.gov/pertussis/pregnant.

Despite the large vaccination rate increases, the researchers warned that the prevalence of Tdap vaccination remains far below the ACIP recommendation that every woman be vaccinated during each pregnancy.

“Increasing vaccination coverage during pregnancy could help reduce the impact of pertussis on infant morbidity and mortality,” they wrote. – by Joe Green


Kerr S, et al. MMWR Morb Mortal Wkly Rep. 2017;doi:10.15585/mmwr.mm6641a3.

Disclosures: Kerr reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.