Yes, Tdap Can Be Administered 1 Week After TD
Tdap can be safely administered as soon as 1 week after TD vaccination, though intervals as short as 2 years are more commonly recommended in guidelines, and even shorter intervals have been documented as safe in clinical practice.
Guideline-Based Recommendations
The ACIP guidelines explicitly support administering Tdap at intervals shorter than the traditional 10-year booster schedule when pertussis protection is needed:
An interval as short as 2 years from the last Td dose is recommended for adults who need pertussis protection, particularly healthcare personnel with direct patient contact and adults with close contact to infants under 12 months 1.
Shorter intervals than 2 years may be used when the benefit of pertussis protection outweighs the risk of local and systemic reactions 1.
For wound management requiring tetanus prophylaxis, Tdap is preferred over Td if the person has not previously received Tdap, regardless of the interval since the last Td 1.
Safety Evidence for Very Short Intervals
Research directly supports the safety of administering Tdap at intervals much shorter than 2 years:
A large safety study of 2,221 healthcare workers found that Tdap administered less than 2 years after Td/TT was non-inferior in safety compared to intervals of 2 years or longer, with no significant increase in moderate or severe injection site reactions 2.
A randomized controlled trial demonstrated that Tdap-IPV administered just 1 month after Td-IPV was safe, with no exacerbation of post-vaccination side effects and no serious vaccine-related adverse events 3.
A Canadian province-wide trial of over 7,000 participants showed that Tdap can be safely administered at intervals as short as 18 months after previous TD/Td, with only slight, clinically insignificant increases in injection site reactions 4.
Clinical Application for 1-Week Interval
Given that safety has been documented at 1-month intervals 3 and guidelines explicitly state "shorter intervals may be used" 1:
A 1-week interval is acceptable when pertussis protection is urgently needed, such as for healthcare workers during outbreaks, new parents/caregivers of infants, or wound management scenarios 1.
The patient should be counseled that mild increases in injection site reactions (pain, erythema, swelling) may occur with shorter intervals, though these are generally minor and self-limited 4.
No serious adverse events, Arthus reactions, or whole limb swelling have been documented even at very short intervals in clinical studies 2, 4.
Important Caveats
Tdap is licensed for only a single lifetime dose in most circumstances; subsequent tetanus/diphtheria boosters should use Td 1.
The only contraindication would be a history of severe Arthus hypersensitivity reaction after a previous tetanus or diphtheria toxoid-containing vaccine, in which case deferral for at least 10 years is recommended 1.
Document the clinical rationale for the short interval (e.g., pertussis outbreak, infant contact, occupational exposure) in the medical record 1.