How often should the Tdap (tetanus, diphtheria, and pertussis) vaccine be administered?

Tdap Vaccine Administration Frequency

Tdap vaccine is given as a single dose to adolescents at age 11-12 years, then routine tetanus-diphtheria boosters (either Td or Tdap) are administered every 10 years throughout adult life, with the important exception that pregnant women receive one dose of Tdap during each pregnancy regardless of prior vaccination history. 1, 2

Standard Vaccination Schedule

Adolescents

• Adolescents should receive one dose of Tdap at age 11-12 years as their first booster after completing the childhood DTaP series. 1, 3, 4
• This single Tdap dose can be administered regardless of the interval since the last tetanus-containing vaccine. 1

Adults

• After receiving the adolescent Tdap dose, adults require tetanus-diphtheria booster vaccination every 10 years for life. 2, 3, 4
• Either Td or Tdap may be used for these decennial boosters since the 2019 ACIP update, providing flexibility in vaccine selection. 2, 3
• Adults who have never received Tdap should receive one dose of Tdap (instead of Td) for their next booster, regardless of when they last received a tetanus-containing vaccine. 2, 3, 4

Elderly Individuals (≥65 years)

• The 10-year booster schedule continues throughout life, including for elderly individuals. 2, 4
• Providers should not miss opportunities to vaccinate persons aged ≥65 years with Tdap if they have never received it. 1
• When feasible, Boostrix should be used for adults aged ≥65 years, though either Tdap product is acceptable. 1

Special Circumstances Requiring Different Intervals

Pregnancy

• Pregnant women must receive one dose of Tdap during each pregnancy, preferably between 27-36 weeks gestation, regardless of prior vaccination history or interval since last tetanus vaccine. 2, 4, 5
• This recommendation applies even if the woman received Tdap less than 10 years ago. 5
• Vaccination as early as possible in the 27-36 week window maximizes maternal antibody transfer to the newborn. 5

Wound Management

• For contaminated or tetanus-prone wounds, a tetanus booster is indicated if more than 5 years have elapsed since the last tetanus-containing vaccine. 2, 3, 4
• For clean, minor wounds, the standard 10-year interval applies. 4
• Tdap is preferred over Td for wound management in patients who have not previously received Tdap. 2, 3, 4

Catch-Up Vaccination

• Adults with incomplete or unknown vaccination history should receive a 3-dose primary series: one dose of Tdap immediately, followed by Td at least 4 weeks later, then a third dose of Td 6-12 months after the second dose. 1, 2, 4
• The vaccination series does not need to be restarted if doses are delayed—simply continue from where the patient left off. 3, 4

Critical Limitations on Tdap Frequency

Tdap is licensed and recommended as a single-dose booster vaccine only, not for multiple administrations in the general population. 1 The only exception to this single-dose recommendation is for pregnant women, who should receive Tdap during each pregnancy. 1

If a dose of Tdap is inadvertently administered to someone who previously received Tdap (outside of pregnancy), this dose should count as the next booster dose of tetanus toxoid-containing vaccine. 1

Important Clinical Pitfalls to Avoid

• Do not administer tetanus boosters more frequently than every 10 years for routine immunization, as this increases the risk of Arthus reactions (severe local hypersensitivity reactions). 3, 4
• Do not delay Tdap vaccination in adults who have never received it—administer as soon as feasible regardless of when they last received a tetanus-containing vaccine. 1, 3
• Do not use DTaP in persons aged ≥7 years; use Tdap or Td instead. 1, 4
• Do not restart the vaccination series if doses are delayed. 3, 4
• For persons with a history of Arthus reaction following a previous tetanus toxoid-containing vaccine, do not administer another tetanus toxoid-containing vaccine until more than 10 years after the most recent dose. 2, 4

Evidence Supporting Current Recommendations

The single-dose Tdap recommendation is based on robust immunogenicity data showing that one dose induces seroprotective antibody levels in virtually all recipients. 6, 7 However, recent evidence demonstrates that a second dose of Tdap approximately 10 years after the first dose is safe, well-tolerated, and immunogenic, with no increased risk of severe local reactions. 8 Despite this evidence, current ACIP guidelines maintain the single-dose recommendation (except for pregnancy) because Tdap products are not licensed for multiple administrations in the United States. 1