FDA OKs Tdap Vaccine for Whooping Cough Protection Before Birth

The FDA announced approval of the first vaccine to be delivered through a pregnant mother to unborn babies for protection in the first 2 months of life.

The tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine Boostrix is to be given during the third trimester of pregnancy to deliver antibodies to the developing baby. Approval was based on Boostrix’s estimated 78% effectiveness in preventing pertussis among infants younger than 2 months of age when administered in this setting.

“While vaccination is the best method for providing protection, infants younger than two months of age are too young to be protected by the childhood pertussis vaccine series,” Peter Marks, MD, PhD, of FDA’s Center for Biologics Evaluation and Research, said in a press release. “This is the first vaccine approved specifically for use during pregnancy to prevent a disease in young infants whose mothers are vaccinated during pregnancy.”

The FDA cited CDC data showing that babies under 6 months old represented 4.2% of pertussis infections in 2021. In nearly a third of cases, these infants required hospitalization.

“Pertussis disease is a highly contagious respiratory illness affecting all age groups. However, babies are at highest risk for getting pertussis and having serious complications from it,” Marks said.

Boostrix’s 78% effectiveness was calculated from a real-world study comparing 108 infants who had pertussis before 2 months of age (including four mothers who received Boostrix during their third trimester of pregnancy) and 183 infants who did not get infected with pertussis (with 18 mothers having received Boostrix during the third trimester of pregnancy).

No excess side effects, on pregnancy or on the baby, were associated with prenatal Tdap vaccination in a randomized, placebo-controlled study. The most commonly reported side effects by individuals who received Boostrix were pain, redness at the injection site, headache, fatigue and gastrointestinal symptoms, according to the FDA.