Tdap Vaccine: Indications, Dosing, and Contraindications
Primary Recommendation
All adolescents aged 11-12 years should receive a single dose of Tdap, and all adults who have never received Tdap should receive one dose immediately, regardless of the interval since their last tetanus-containing vaccine. 1, 2 Pregnant women must receive Tdap during each pregnancy between 27-36 weeks gestation, regardless of prior vaccination history. 1, 3
Indications by Population
Adolescents (11-18 years)
- Routine booster: Administer one dose of Tdap at age 11-12 years, preferably, regardless of interval since last tetanus-containing vaccine 1, 2
- If the 11-12 year dose is missed, adolescents aged 13-18 years should receive Tdap provided the childhood DTaP series is complete 2
- For adolescents with incomplete or no prior tetanus immunization, administer a 3-dose series: one dose of Tdap, followed by Td ≥4 weeks later, then a third dose of Td 6-12 months after the second 1, 2
Adults (19-64 years)
- All adults who have never received Tdap should receive one dose as soon as feasible, regardless of when they last received a tetanus-containing vaccine 1, 2
- After receiving Tdap, continue with Td boosters every 10 years 1, 4
- For adults with no prior tetanus immunization, administer a 3-dose primary series: Tdap first, then Td ≥4 weeks later, then Td 6-12 months after the second dose 1, 2
Adults ≥65 years
- All adults aged ≥65 years who have never received Tdap should receive one dose, regardless of age 2
- Boostrix is preferred when feasible for this age group, though either Tdap product (Boostrix or Adacel) is acceptable and immunogenic 2
- Safety and immunogenicity data from 2012 demonstrate that Tdap is as safe and effective in adults ≥65 years as in younger adults 2, 5
Pregnant Women
- Administer one dose of Tdap during each pregnancy between 27-36 weeks gestation, preferably during the earlier part of this window 1, 2, 3
- This recommendation applies regardless of prior Tdap vaccination history 1, 3
- Pregnancy is not a contraindication to Tdap; the vaccine may be safely given at any time during pregnancy if needed for wound management or outbreaks 1, 3
- If not vaccinated during pregnancy, adolescent mothers should receive Tdap immediately postpartum to reduce transmission risk to the infant 1
Healthcare Personnel
- All healthcare workers who have not previously received Tdap should receive one dose as soon as feasible 2
- Priority should be given to workers with direct contact with infants younger than 12 months 2
Dosing Schedule
Standard Administration
- Dose: 0.5 mL administered intramuscularly 2, 6
- Site: Deltoid muscle of the upper arm for adolescents and adults; anterolateral thigh for infants 2, 6
- Preparation: Shake vigorously to obtain a homogeneous, turbid, white suspension before administration 6
Routine Booster Intervals
- After completing the primary series and receiving Tdap, administer Td or Tdap boosters every 10 years 1, 2, 4
- Since 2019, ACIP guidelines allow flexibility: either Td or Tdap may be used for decennial boosters 2, 4
Wound Management
- For clean, minor wounds: No tetanus toxoid needed if last dose was within 10 years; if >10 years, give Tdap (if never received) or Td 2
- For contaminated or tetanus-prone wounds: Tetanus toxoid needed if last dose was >5 years ago; Tdap is preferred if never received, otherwise Td 1, 2, 4
- For patients with unknown or incomplete vaccination history, administer both tetanus vaccine and tetanus immune globulin (TIG) 250 units IM in separate syringes at different anatomic sites 2
Catch-Up Vaccination
- For unvaccinated persons aged 7-18 years, administer a 3-dose series: one dose of Tdap, followed by Td ≥4 weeks later, then Td 6-12 months after the second dose 2
- For adults with uncertain vaccination history, treat as unvaccinated and administer the complete 3-dose primary series 2
- Serologic testing for tetanus and diphtheria antitoxin levels (≥0.1 IU/mL) may be used to confirm prior vaccination; if positive, only a single dose of Tdap is needed 1, 2
Contraindications
Absolute Contraindications
- History of anaphylaxis to any vaccine component or after a previous dose of any tetanus toxoid-, diphtheria toxoid-, or pertussis antigen-containing vaccine 2, 6
- Encephalopathy within 7 days of a prior pertussis-containing vaccine that is not attributable to another identifiable cause—in this case, use Td (without pertussis) instead of Tdap 2, 6
Precautions (Risk-Benefit Considerations)
- Guillain-Barré syndrome ≤6 weeks after a previous tetanus toxoid dose: Vaccination may proceed, but Tdap is preferred over Td 2
- Progressive neurologic disorder or uncontrolled epilepsy: Withhold the pertussis component and administer Td instead 2
- History of Arthus reaction following a previous tetanus toxoid-containing vaccine: Do not administer any tetanus toxoid-containing vaccine until >10 years after the most recent dose, even for wound management 2, 7
Critical Clinical Pitfalls to Avoid
Frequency Errors
- Do not administer tetanus boosters more frequently than every 10 years for routine immunization—this increases the risk of Arthus-type hypersensitivity reactions (severe local reactions with pain, swelling, and induration developing 4-12 hours post-injection) 2, 7
- Tdap is licensed as a single-dose booster vaccine only, not for multiple administrations in the general population (except pregnant women, who receive Tdap during each pregnancy) 7
Age-Inappropriate Vaccine Selection
- Do not administer DTaP to persons aged ≥7 years—use Tdap or Td instead, as the higher diphtheria toxoid content in DTaP can cause severe reactions in older children and adults 2, 6
- Do not use Boostrix in adults >18 years if Adacel is indicated, though if Boostrix is inadvertently given to an adult >19 years, count it as the Tdap dose and do not repeat 1
Timing Errors
- Do not delay Tdap vaccination in adults who have never received it—administer immediately regardless of interval since last Td dose 2, 7
- Do not restart the vaccination series if doses are delayed; simply continue from where the patient left off 2
Pregnancy-Specific Errors
- Do not withhold Tdap during pregnancy due to concerns about safety—no evidence exists of risk from inactivated vaccines or toxoids in pregnant women 1, 3
- Do not administer Tdap in the first trimester when feasible; prefer the second or third trimester (27-36 weeks) to minimize perception of association with adverse pregnancy outcomes 1
Documentation Failures
- Permanent vaccination records must include vaccine type, manufacturer, anatomic site, route, administration date, and facility 2
- Encourage patients to keep personal vaccination records to minimize unnecessary repeat vaccinations 2
Special Circumstances Permitting Shorter Intervals
Outbreak Situations
- Tdap may be administered at intervals <10 years since the last Td during periods of increased community pertussis activity or outbreaks, particularly for adults with comorbid conditions at higher risk for pertussis complications 2
Wound Management
- For contaminated or tetanus-prone wounds, Tdap is preferred over Td for adults vaccinated >5 years earlier who require tetanus prophylaxis and have not previously received Tdap 2, 4
- Adults who completed the primary series and received tetanus vaccine <5 years earlier do not require additional vaccination for wound management 2
Repeat Tdap Dosing
- Studies demonstrate that a second dose of Tdap approximately 10 years after a previous dose is well tolerated and immunogenic, with robust antibody responses to all pertussis antigens 8
- However, current ACIP guidelines do not support a universal recommendation for a second dose of Tdap for the general population 1
Product-Specific Information
Licensed Tdap Products
- Boostrix (GlaxoSmithKline): Licensed for persons aged ≥10 years 1, 2, 6
- Adacel (Sanofi Pasteur): Licensed for persons aged 11-64 years (now extended to include adults ≥65 years per updated guidelines) 1, 2
Pregnancy Registries
- Healthcare providers should report Tdap vaccination during pregnancy to manufacturer registries: Boostrix (888-825-5249) or Adacel (800-822-2463) 1