FDA clears GSK’s Boostrix for use in pregnancy

The FDA has approved the use of GlaxoSmithKline’s Boostrix (Tdap) vaccine for use in the third trimester of pregnancy to prevent pertussis (whooping cough) in infants younger than two months old.
According to the Centers for Disease Control and Prevention (CDC), 4.2% of the total cases of pertussis reported in the US in 2021 were in infants younger than six months of age, and approximately 31% required hospitalisation. Boostrix is already used for active booster immunisation in children aged 10 to 18 years against tetanus, diphtheria and pertussis, and has been previously approved for use in pregnancy to protect the mother.
The determination of the effectiveness of Boostrix administered during the third trimester to prevent pertussis among infants younger than two months was based on a re-analysis of Boostrix-relevant data. 
108 cases of pertussis in infants younger than two months (including four cases where the mother received Boostrix during the third trimester) and 183 control infants who didn’t have pertussis (including 18 whose mother received Boostrix in the third trimester) resulted in a preliminary estimate of Boostrix being 78% effective.
Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, stated: “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. 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. This is the first vaccine approved specifically for use during pregnancy to prevent a disease in young infants whose mothers are vaccinated during pregnancy.”