A pregnant woman at 28 weeks of gestation is given a Tdap vaccine. What is the primary reason for administering this vaccine during pregnancy?

Correct option is B

Ans. (b) To provide passive immunity to the newborn against pertussis
Sol. The Tdap vaccine (Tetanus, Diphtheria, and Acellular Pertussis) is administered during pregnancy (usually between 27–36 weeks of gestation) primarily to passively transfer antibodies to the newborn against pertussis (whooping cough). Newborns are at high risk for severe pertussis infections, and since they cannot be vaccinated immediately after birth, maternal antibodies provide essential early protection.
Explanation of each option:
· (a) To protect the mother from developing tetanus – Partially correct, but the primary reason is newborn immunity.
· (b) To provide passive immunity to the newborn against pertussis – Correct answer. Antibodies pass through the placenta, protecting the infant until they receive their own vaccinations.
· (c) To prevent the mother from contracting diphtheria – Incorrect, as diphtheria is rare, and the primary goal is newborn protection.
· (d) To enhance the newborn's response to future vaccinations – Incorrect, as the vaccine provides immediate passive immunity, not an enhanced vaccine response.