Although a vaccine during pregnancy can prevent pertussis during an infant’s first two most vulnerable months, the disease, also commonly known as whooping cough, has been rising in the U.S. over the past two years. In 2024, there were 10 reported deaths and 16 in 2025, mostly among infants under 1 year old.
A recent report has compiled the most up-to-date safety and effectiveness data on the vaccine, which you should consider for your reporting.
Rates of pertussis in 2026 are lower than in 2025 but still following a similar trajectory as the past two years. Given national case counts and state-level vaccination rates remaining below target, the new study’s findings are worth sharing with the public, particularly in states like California, Washington and Ohio, where rates are the highest. (AHCJ hosted a webinar in May that shared highlights of the findings and how best to communicate them. Journalists can find a list of resources, including the slides shown during the webinar, here.)
Since babies cannot receive the DTaP (diphtheria-tetanus-pertussis) vaccine until 2 months old, the most effective way to protect them is through passive immunization from vaccination during gestation. Since 2012, the CDC has recommended giving expectant mothers the Tdap (tetanus-diphtheria-pertussis) vaccine between 27 and 36 weeks of pregnancy. The fetus receives their mother’s antibodies in response to the vaccine, and that protection remains robust for several months after birth, with some level of protection lasting up to age 1.
But rates of Tdap vaccination during pregnancy fell during and since the pandemic, with barely 60% of pregnant people receiving the vaccine. Pertussis is naturally cyclical, with peaks every 3-5 years, and cases have ranged from 10,000 to 20,000 cases most years* since the early 2000s, except one spike of 48,277 cases in 2012.
*Editor’s note: The previous link goes to a Web Archive version as the original page is no longer available on the CDC website.
However, after a few years of very low levels following the pandemic — a common trend for many respiratory diseases — pertussis cases have jumped above the usual pre-pandemic highs for a variety of reasons, including inadequate maternal immunization.
Vaccine hesitancy
Hesitancy about childhood vaccines has been rising in the U.S. since the pandemic, with an accompanying decline in vaccination rates, though overall childhood vaccination rates remain high. In the absence of robust federal leadership on vaccine confidence, the Vaccine Integrity Project, from the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP), and the nonprofit Evidence Foundation collaborated to produce a systematic review and meta-analysis on the safety and effectiveness of Tdap vaccination during pregnancy. The most recent prior review of the evidence was a 2020 CDC MMWR review that covered data through 2019.
The new review includes evidence from 91 randomized controlled trials and observational studies, including 62 new studies since the last review. In terms of safety, the analysis found no increased risk with vaccination, compared to pregnancies without vaccination, of stillbirth, preterm birth, preeclampsia, eclampsia, chorioamnionitis, placental conditions, gestational diabetes, or any other adverse events. They also found no increased risk of infant death, congenital defects, NICU admission, neonatal sepsis, growth restriction, or low birth weight.
Meanwhile, the combined data showed a lower risk of pertussis infections, complications, emergency room visits, and hospitalizations in infants exposed to Tdap vaccination during pregnancy. Only two studies evaluated the risk of pertussis-related death, and they suggested the vaccine reduces the risk of death, but the conclusions are less conclusive since death is already a rare outcome from pertussis in the U.S.
As webinar speakers Elizabeth Marnik, Ph.D., and Bertha Hidalgo, Ph.D., MPH, explained during the May AHCJ webinar, pregnancy is a “window of persuasion,” when people encounter vaccine misinformation while already feeling overwhelmed with all the things they are and aren’t “supposed” to do. Their slides on the challenges of debunking misconceptions about vaccines, how to “pre-bunk,” and the loaded language often used in discussions of vaccination are particularly helpful for journalists preparing stories about this review or any pregnancy vaccine.
