Pertussis rates in newborns have dropped significantly since pregnant women started getting vaccinated, according to a new study from the Centers for Disease Control and Prevention (CDC).
However, only about half of pregnant women are following the CDC’s recommendation to get a tetanus, diphtheria and acellular pertussis (Tdap) vaccine. The vaccine is recommended during weeks 27-36 of each pregnancy to pass protective antibodies to infants.
“Getting Tdap during pregnancy offers infants the best protection before they are old enough to receive their whooping cough vaccines,” José Romero, M.D., FAAP, director of the CDC’s National Center for Immunization and Respiratory Diseases, said in a press release. “This protection is critical because those first few months are when infants are most likely to have serious complications, be hospitalized or die if they get whooping cough.”
Researchers from the CDC analyzed data on pertussis cases from 2000-’19, comparing rates before and after vaccination of pregnant women began in 2011.
There were just over 19,000 cases of pertussis in infants under 2 months during the study period, according to “US Infant Pertussis Incidence Trends Before and After Implementation of the Maternal Tetanus, Diphtheria, and Pertussis Vaccine” (Skoff TH, et al. JAMA Pediatr. Feb. 6, 2023).
There were about 165 cases per 100,000 infants under 2 months annually in the period before maternal vaccination. In the vaccination period, average annual cases dropped to 122 per 100,000. Rates were especially low in recent years, falling to 81 per 100,000 infants under 2 months from 2017-’19. Researchers did not see a similar decrease in cases among children 6 months through 11 months who were not dependent on maternal vaccination.
Despite the protection Tdap vaccination provides, only about 55% of pregnant women were vaccinated in 2019.
“Everyone who is pregnant should feel confident in knowing that the Tdap vaccine is safe and effective,” said Linda Eckert, M.D., American College of Obstetricians and Gynecologists’ liaison to the CDC’s Advisory Committee on Immunization Practices. “Knowing that Tdap vaccination during pregnancy protects nine in 10 babies from being hospitalized with whooping cough, I strongly recommend this vaccine to all my pregnant patients for their peace of mind and for their family’s health and well-being.”