What is the recommended timing for administering Tdap during pregnancy?

The recommended timing for administering the Tdap vaccine during pregnancy is between 27 and 36 weeks gestation. This timing is crucial because it allows the mother to develop adequate antibodies that can be passed to the fetus, providing important protection against pertussis (whooping cough) during the early weeks of life when the infant is most vulnerable. Administering the vaccine in the late third trimester maximizes the transfer of these maternal antibodies and helps to ensure that the newborn has some degree of immunity until they can receive their own immunizations.

The timing also aligns with public health guidelines that recommend this vaccination period during each pregnancy to effectively boost passive immunity in the infant. Vaccination at this stage not only protects the baby but also reduces the risk of disease in pregnant women, who may experience more severe complications from pertussis infection.