From the Guidelines
The Tdap vaccine is a crucial immunization for adolescents and adults to protect against tetanus, diphtheria, and pertussis.
Key Points
- It is advised to administer a single dose of Tdap vaccine to individuals 11 to 12 years old, and to adults who have not previously received a Tdap vaccine, replacing one of the Td booster doses 1.
- The vaccine should be given as a 0.5 mL dose, administered intramuscularly.
- For pregnant women, a Tdap vaccine dose is recommended during each pregnancy, ideally between 27 and 36 weeks of gestation 1.
- Booster doses of Td vaccine are recommended every 10 years, with one of these booster doses being a Tdap vaccine 1.
Vaccine Formulations
There are two Tdap products licensed for use in adolescents and adults: Boostrix and Adacel 1.
- Boostrix is licensed for persons aged ≥10 years and contains three pertussis antigens (PT, PRN, and FHA).
- Adacel is licensed for persons aged 10–64 years and contains five pertussis antigens (PT, PRN, FHA, and FIM). Both vaccines are formulated with reduced quantities of toxoids and antigens compared to pediatric DTaP vaccines.
Administration and Booster Schedule
The Tdap vaccine is typically administered as a single dose, with booster doses of Td vaccine recommended every 10 years 1. In pregnant women, the Tdap vaccine dose should be administered during each pregnancy, ideally between 27 and 36 weeks of gestation 1. Healthcare providers should follow the recommended schedule and guidelines for administering Tdap and Td vaccines to ensure optimal protection against tetanus, diphtheria, and pertussis.
From the Research
Definition and Purpose of Tdap Vaccine
- The Tdap vaccine is a combined tetanus, diphtheria, and acellular pertussis vaccine used to protect against tetanus, diphtheria, and pertussis [(2,3)].
- The vaccine is designed for use in adolescents and adults, and is typically administered as a single dose to replace the tetanus and diphtheria toxoid vaccine (Td) for booster immunization [(2,4)].
Components and Efficacy
- The Tdap vaccine contains pertussis toxoid, filamentous hemagglutinin, pertactin, and fimbriae types 2 and 3, which elicit robust immune responses against pertussis, tetanus, and diphtheria antigens 2.
- Studies have shown that the Tdap vaccine is effective in inducing protective antibody concentrations against diphtheria and tetanus, with seroprotection rates of >94% and nearly 100%, respectively [(2,3)].
- The vaccine has also been shown to be noninferior to the Td vaccine in terms of immunogenicity and reactogenicity 3.
Safety and Administration
- The Tdap vaccine has been found to be generally well-tolerated, with a safety profile similar to that of the Td vaccine [(2,3)].
- The vaccine can be administered to individuals aged 10-64 years, with a single dose recommended to replace the Td vaccine for booster immunization [(3,4)].
- Repeated doses of the Tdap vaccine have been found to be safe, with no significantly elevated risk of adverse events 5.
Vaccination Coverage and Recommendations
- According to the Advisory Committee on Immunization Practices (ACIP), the Tdap vaccine is recommended for adolescents and adults aged 11-64 years, with a single dose replacing the Td vaccine for booster immunization [(4,6)].
- Vaccination coverage among adults has been found to be low, with estimated Tdap coverage of 5.9% in 2008 6.
- Health-care providers are recommended to administer the Tdap vaccine to adults aged 18-64 years whose most recent tetanus vaccination was ≥10 years prior, with a shorter interval of 2 years for health-care personnel and individuals with infant contact 6.