The US Food and Drug Administration (FDA), announced Friday the approval of Boostrix (tetanus vaccine, reduced diphtheriatoxoid and acellular pertussis vaccination adsorbed). [Tdap]For infants under two months old, a third-trimester immunization is recommended to prevent pertussis (whooping cold)
The FDA’s approval of Boostrix already included its use during pregnancy to protect the mother. The FDA has now approved Boostrix only for use during pregnancy to prevent pertussis in infants born under two months.
In 2005, the vaccine was approved for use by adolescents aged 10-18 against whooping cough, diphtheria, and tetanus.
The youngest infants are most likely to get whooping cough.
The US sees frequent outbreaks of whooping cough; with the most serious cases – including hospitalizations and deaths – occurring in infants younger than two months old who are too young to be protected by the childhood pertussis vaccine series.
According to the Centers for Disease Control and Prevention, 4.2% of all cases of respiratory disease in the US in 2021 was reported by infants aged less than 6 months. The Centers for Disease Control and Prevention (CDC) estimated that 31% of those hospitalized required admission.
Boostrix vaccines are given to pregnant women during pregnancy. They boost antibodies that are then transferred to the baby.
The effectiveness of Boostrix in the third trimester for infants was determined by a reanalysis of the Boostrix-relevant data taken from an observational study on Tdap vaccination effectiveness.
This re-analysis included data from 108 infants with pertussis under 2 months old (including four cases whose mothers received Boostrix in the third trimester), and 183 infants who were not affected by pertussis. The preliminary estimate of Boostrix’s effectiveness in preventing pertussis was 78% when administered in the third trimester.
In a randomized controlled study, a non-U.S. formulation Boostrix was tested for safety during third trimester.
The study included 680 pregnant people, out of whom 340 received Boostrix, and 340 were given saline placebo. The placebo recipients were then vaccinated after childbirth. These side effects were similar to those reported by pregnant recipients of Boostrix after childbirth.
The study didn’t identify any vaccine-related adverse reactions in pregnancy, on the fetus, or on newborns.
“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,”Peter Marks M.D., Ph.D. director of the FDACenter for Biologics Evaluation and Research. “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.”
