What is the recommended use and administration of the Tdap (Tetanus, Diphtheria, and Pertussis) vaccine?

Tdap Vaccine: Recommendations and Administration Guidelines

Tdap (Tetanus, Diphtheria, and acellular Pertussis) vaccine should be administered to all adolescents aged 11-12 years as a single dose, and to adults as either a primary dose or booster, with specific recommendations for pregnant women to receive Tdap during each pregnancy regardless of prior vaccination history. 1

Overview and Available Products

Two Tdap vaccines are licensed for use in the United States:

• Boostrix (GlaxoSmithKline): Approved for persons aged ≥10 years
• Adacel (Sanofi Pasteur): Approved for persons aged 10-64 years

Both vaccines contain tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis components, administered as a 0.5 mL intramuscular injection, preferably in the deltoid muscle 1.

Routine Recommendations by Age Group

Adolescents (11-18 years)

• Single dose of Tdap at age 11-12 years (preferred age)
• Should receive Tdap even if they previously received Td
• If Tdap was previously administered between ages 7-10 years as part of catch-up vaccination, they should still receive the routine adolescent Tdap dose at age 11-12 years 1, 2

Adults (≥19 years)

• Single dose of Tdap if not previously received
• For adults aged ≥65 years, either Tdap product is considered valid, though Boostrix is preferred as it's specifically approved for this age group 1

Pregnant Women

• Tdap during each pregnancy, preferably between 27-36 weeks gestation
• This recommendation applies regardless of prior Tdap vaccination history
• Studies show 77.7% effectiveness in preventing pertussis in infants <2 months, increasing to 90.5% against hospitalized cases 3

Updated Booster Recommendations (2019)

The 2019 ACIP update allows more flexibility in booster doses:

• Either Td or Tdap can be used for:
  • Decennial (10-year) booster doses
  • Tetanus prophylaxis for wound management
  • Catch-up immunization in persons aged ≥7 years with incomplete vaccination history 1

Administration Guidelines

Dosage and Administration

• Dose: 0.5 mL administered intramuscularly
• Preferred site: Deltoid muscle
• May be administered simultaneously with other vaccines at different anatomical sites 1

Simultaneous Administration

• Tdap and meningococcal conjugate vaccine (MCV4) can be administered during the same visit
• Use separate syringes at different anatomic sites
• Administering all indicated vaccines during a single visit increases likelihood of complete vaccination 1, 2

Interchangeable Use

• Either Tdap product (Boostrix or Adacel) can be used regardless of which DTaP product was used for childhood vaccination 1

Special Situations

Catch-up Vaccination

• For persons aged ≥7 years with incomplete or unknown vaccination history, Tdap can be the first dose in a catch-up series
• The vaccine series does not need to be restarted regardless of time elapsed between doses 2

Inadvertent Administration

• If DTaP is inadvertently given to someone aged 7-10 years, count as the adolescent Tdap dose
• If DTaP is given to someone ≥11 years, count as the Tdap dose with no additional Tdap needed 1

Interval Between Td and Tdap

• ACIP now recommends that Tdap should be administered regardless of interval since the last tetanus or diphtheria toxoid-containing vaccine
• The benefits of protection against pertussis outweigh the potential risk for adverse events 1

Safety and Efficacy

• Tdap revaccination approximately 10 years after a previous dose is well-tolerated and immunogenic 4
• Vaccine effectiveness against pertussis is estimated at 65.6% in adolescents during outbreak settings 5
• Local reactions (pain, redness, swelling at injection site) are common but generally mild 6, 7
• Syncope can occur after vaccination, particularly in adolescents; a 15-20 minute observation period following vaccination is recommended 1

Preventing Adverse Events

• Attention to proper vaccination technique, including appropriate needle length and standard routes of administration
• Observation for 15-20 minutes after vaccination to monitor for syncope
• Be aware of potential administration errors involving tetanus toxoid-containing vaccines 1

Tdap vaccination remains a critical component of public health strategy to reduce morbidity and mortality from tetanus, diphtheria, and especially pertussis, which continues to cause significant disease burden despite vaccination efforts.