We have a 63-year-old patient who states she had tetanus as a child. She does not know whether she ever had any tetanus-containing vaccines in her lifetime. Should Tdap be given to this patient, and is it safe?

A history of tetanus disease is not a reason to avoid tetanus-containing vaccines. Tetanus disease does not produce immunity because of the very small amount of toxin required to produce illness. As long as your patient has no other contraindications, she should receive Tdap now. If she has no documentation of prior tetanus vaccination, she should receive a complete 3-dose primary series (dose #1 of Tdap, followed by dose #2 of Td or Tdap 4–8 weeks later, and dose #3 of Td or Tdap 6–12 months after dose #2).