Boostrix vs Adacel for Tdap Vaccination
When feasible, Boostrix should be used for adults aged ≥65 years instead of Adacel, though either vaccine administered to a person aged ≥65 years is immunogenic and would provide protection against tetanus, diphtheria, and pertussis. 1
Comparison of the Two Tdap Vaccines
Key Differences
FDA Approval Age Range:
Pertussis Antigen Composition:
Immunogenicity
Boostrix
- Immune responses to diphtheria and tetanus were noninferior to comparator Td vaccine 1
- Pertussis immune responses were noninferior to those observed following a 3-dose primary DTaP series 1
- Geometric mean concentrations for antibodies to pertussis antigens increased 7.4-fold to 13.7-fold over baseline levels 1
- In adults 19-64 years, booster responses to pertussis antigens were observed in 77.2% (PT), 96.9% (FHA), and 93.2% (PRN) of recipients 2
Adacel
- Antibody responses to diphtheria and tetanus were noninferior to comparator Td vaccine 1
- Some pertussis antigens did not meet predefined noninferiority criteria as agreed upon by FDA 1
- Still demonstrated a 4.4-fold to 15.1-fold increase in anti-pertussis antibodies 1
- ACIP concluded that Adacel likely would provide protection in adults aged ≥65 years 1
Safety Profile
- Both vaccines have comparable safety profiles to Td vaccine 1
- In a direct comparison study, injection site reactions and fever were reported significantly more often with Adacel than with Boostrix 2
- Fatigue preventing normal daily activities was reported by a small but significantly greater percentage of Boostrix recipients (2.5%) than Adacel recipients (1.2%) 2
Recommendations for Different Age Groups
Adults ≥65 Years
- When feasible, Boostrix should be used for adults aged ≥65 years 1
- Boostrix has been specifically studied in and found to be immunogenic in subjects ≥65 years, with a safety profile comparable to US-licensed Td vaccine 3
- However, either vaccine administered to a person ≥65 years is considered valid and would provide protection 1
Adults 19-64 Years
- Both vaccines are acceptable options for this age group 1
- Boostrix has demonstrated immunogenicity and safety in adults 19-64 years of age 2
- Adacel is FDA-approved for this age range 1
Adolescents 10-18 Years
- Both vaccines are approved and recommended for this age group 1
Clinical Decision Algorithm
For adults ≥65 years:
- Preferred: Boostrix (FDA-approved for this age group)
- Alternative: Adacel (if Boostrix is unavailable)
For adults 19-64 years:
- Either vaccine is appropriate
- Consider Boostrix if patient reports previous injection site reactions, as it showed fewer local reactions in comparative studies 2
For adolescents 10-18 years:
- Either vaccine is appropriate
For wound management:
- Either Tdap vaccine is preferred over Td for wound management in adults who have not previously received Tdap 1
Important Considerations
- Do not miss an opportunity to vaccinate with Tdap due to product preference; providers may administer the Tdap vaccine they have available 1
- Only a single dose of Tdap is recommended across all age groups, except for pregnant women who should receive Tdap during each pregnancy 1
- After receipt of Tdap, persons should continue to receive Td for routine booster immunization against tetanus and diphtheria 1
Pitfalls to Avoid
- Do not withhold vaccination if the preferred product is unavailable; either vaccine provides protection against pertussis, tetanus, and diphtheria 1
- Do not administer DTaP (pediatric formulation) instead of Tdap to persons aged ≥7 years 1
- Do not administer multiple doses of Tdap (except during pregnancy), as this is not currently recommended 1
- Do not delay Tdap administration to increase the interval from previous Td vaccination; Tdap should be administered regardless of interval since the last tetanus or diphtheria toxoid-containing vaccine 1