I try to avoid controversy and conflict when I can, so a quick disclaimer- I am not writing this to argue with anti-vaxers, I am just getting some information out there for people who are interested in why doctors recommend Tdap in pregnancy and who it protects.
The Tdap vaccination was developed because it was recognized that the pertussis immunization we give in childhood- the “acellular” form- Dtap, didn’t create lifelong antibodies as was originally thought, so adolescents and adults needed a booster to further protect them from infection.
So why do pregnant women get one of these with each pregnancy? I promise it’s not just our attempt to make your arm sore! I’ve had 2 Tdap vaccines in the last 8 years between the required vaccination for medical school and having my baby girl, so I understand! The most susceptible group to severe pertussis infection and death are infants under 3 months, and we don’t start immunizations until 2 months, so there is a window of time they are unprotected. When given to pregnant women between 26-37 weeks, the antibodies that mom makes to pertussis are available to newborns and help protect them if exposed to pertussis before vaccines are administered. We also strongly encourage all family members who will be in contact with the baby to receive a Tdap as well, to “cocoon” the infant from potential exposure. I sent my mom, my 10 month olds’ primary caregiver, to her doctor to get her Tdap before watching my daughter for this very reason! And my husband received his Tdap in our OB’s office when I did as well.
Why do we care? Isn’t pertussis just a bad cough? No, not exactly. Per the CDC, half of infants that develop pertussis under age 1 end up requiring hospitalization, and of those, 1 in 4 develop pneumonia and 1-2 per 100 will die. Scary stats.