Does getting a Tdap shot as an adult help prevent Pertussis in infants?
Adults cannot get a Tdap shot to directly protect an infant because the vaccine does not work that way. However, if a pregnant woman gets the Tdap shot, her body makes antibodies that cross the placenta to the baby. This gives the newborn temporary protection until they can start their own vaccine series. Research shows that babies born to vaccinated mothers have higher levels of protective antibodies at six months compared to those born to unvaccinated mothers 1.
What the research says
A study found that infants born to mothers who received the pertussis vaccine during pregnancy had higher concentrations of anti-pertussis toxin antibodies at six months. These mothers-derived antibodies showed stronger binding strength and better ability to inhibit specific targets than what infants developed after just two doses of their own vaccine 1. This transfer of immunity is the primary way an adult shot helps an infant.
Unvaccinated infants are at high risk because they are too young to receive the full vaccine series. Pertussis causes a substantial disease burden in this specific group, along with pregnant women 2. Data from a meta-analysis indicates that being unvaccinated with the DTP vaccine is a significant factor associated with severe pertussis in children 5.
What to ask your doctor
- When should I get the Tdap shot during my pregnancy for the best infant protection?
- Does my baby's antibody level at six months depend on whether I was vaccinated?
- What are the signs of severe pertussis I should watch for in my infant?
- How does the timing of my Tdap shot affect the amount of antibodies passed to the baby?
This question is drawn from common patient questions about Primary Care & Family Medicine and answered using cited medical research. We do not provide individualized advice.