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Td or Tdap Vaccine Dosing

Version 20.2


Below are the recommendations for the use of Td or Tdap for the decennial Td booster and catch-up immunization schedule for persons aged > 7 years with incomplete or unknown vaccination history.

Routine Vaccination

  • Adolescents age 11-12 years: 1 dose Tdap.
  • Pregnancy: 1 dose Tdap during each pregnancy, preferably in early part of gestational weeks 27-36.
  • Tdap may be administered regardless of the interval since the last tetanus - and diphtheria-toxoid-containing vaccine.

Catch-up Vaccination

  • Adolescents age 13-18 years who have not received Tdap: 1 dose Tdap, then Td or Tdap booser every 10 years Decennial booster dose.
  • Age 7-18 years not fully vaccinated with DTaP: 1 dose Tdap as part of the catch-up series (preferably the first dose); if additional doses are needed use Td or Tdap.

NoteFully vaccinated with DTap is 5 valid doses of DTaP or 4 valid doses of DTaP if dose 4 was administered at age 4 years or older.

  • Age 7-18 years and > 19 years, who have never been vaccinated against pertussis, tetanus or diphtheria: Should receive a series of three tetanus and diphtheria toxoid-containing vaccines, which includes at least 1 dose of Tdap. The preferred schedule is a dose of Tdap followed by a dose of either Td or Tdap at least 4 weeks afterward and another dose of either Td or Tdap 6 to 12 months later.
  • Tdap administered at 7-10 years:
  • Age 7-9 years: Received Tdap between this age should receive the routine Tdap dose at age 11-12 years.
  • Age 10 years: Received Tdap at 10 years do not need to receive the routine Tdap dose at age 11-12 years.

  • DTaP inadvertently administered at or after age 7 years:
  • Age 7-9 years: DTaP may count as part of catch-up series. Routine Tdap dose at age 11-12 years should be administered.
  • Age 10-18 years: Count dose of DTaP as the adolescent Tdap booster.

Unintentional Administration

  • Fully vaccinated children aged 7-10 years: If a fully vaccinated child aged 7-9 years received Tdap, the Tdap dose should not be counted as valid.
  • The adolescent Tdap dose should be administered as recommended when this child is aged 11-12 years.
  • The preferred age at administration for the adolescent Tdap dose is 11-12 years.
  • If Tdap is administered at age 10 years, the Tdap dose may count as the adolescent Tdap dose.