Tdap Booster
This patient requires a Tdap booster (Answer C) because she sustained a head injury from a fall 12 years after her last tetanus vaccine, and the wound should be considered tetanus-prone, requiring vaccination when ≥5 years have elapsed since the last dose. 1, 2
Wound Classification and Critical Time Interval
Head injuries from falls are classified as contaminated/tetanus-prone wounds because they may be contaminated with dirt, soil, or other environmental pathogens, which determines a critical time interval of 5 years (not 10 years) for booster administration 1, 3
The most common error in tetanus prophylaxis is confusing the 10-year routine booster interval with the 5-year interval required for contaminated wounds 1
Vaccination Algorithm for This Patient
Since this patient has ≥3 previous doses (assuming completed primary series) and the last dose was ≥5 years ago (12 years), she requires a tetanus toxoid-containing vaccine WITHOUT tetanus immune globulin (TIG) 1, 2
Tdap is strongly preferred over Td alone for adults who have not previously received Tdap or whose Tdap history is unknown, as this provides protection against pertussis in addition to tetanus and diphtheria 1, 2
TIG is not indicated because the patient has a documented complete primary vaccination series and is not severely immunocompromised 2
Why Tdap Over Plain Tetanus Shot
The CDC Advisory Committee on Immunization Practices recommends Tdap as the preferred choice for persons aged ≥11 years when tetanus toxoid-containing vaccine is indicated for wound management, particularly if prior Tdap history is unknown 2
Tdap should not be delayed when indicated and should be administered regardless of the interval since the last tetanus or diphtheria toxoid-containing vaccine 4
The 12-year interval since last vaccination is well beyond any safety concerns, and more frequent dosing than recommended guidelines is the actual concern, not administering Tdap at this interval 2, 5
Clinical Pitfalls to Avoid
Do not wait to give tetanus prophylaxis when >5 years have elapsed for tetanus-prone wounds 2
Do not assume the patient previously received Tdap without documentation—if unknown, give Tdap rather than Td 2
Do not give TIG to patients with documented complete primary vaccination series unless they are severely immunocompromised or have HIV infection 2
Failure to provide tetanus vaccination when needed could result in preventable illness, whereas unnecessary vaccination at this interval is unlikely to cause harm 1