Q. Are family members and other caregivers of an infant supposed to get the Tdap vaccine for whooping cough once in a lifetime or should they also get the vaccine again before a new baby is born?
A. Adults are recommended to get only a single dose of the Tdap vaccine, with one exception: Pregnant women are recommended to get one dose of the Tdap vaccine during each pregnancy. This is because maternal antibodies will protect the baby in the months before the baby is protected by an active vaccine. Because the goal of vaccination is to leverage maternal antibodies, the recommendation is specific for 27-36 weeks of gestation. This timing takes into account the time needed to generate maternal antibodies and transfer them to the baby, therefore, maximizing the baby’s opportunity for protection.