A 60-year-old male with no comorbidities who completed a full rabies vaccination series 30 years ago now presents with a category III cat bite; what rabies post‑exposure prophylaxis regimen should he receive?

Rabies Post-Exposure Prophylaxis for Previously Vaccinated Individual with Category III Bite

Direct Recommendation

This patient requires only 2 doses of rabies vaccine (1.0 mL intramuscularly on days 0 and 3) and should NOT receive rabies immune globulin (HRIG). 1, 2, 3

Rationale for Simplified Regimen

Previously vaccinated persons maintain immunological memory even decades after initial vaccination, and the simplified 2-dose schedule leverages this anamnestic response rather than requiring the full primary series. 4, 1, 2 The key principle is that prior vaccination—even 30 years ago—has primed the immune system, and re-exposure triggers a rapid memory response that makes HRIG unnecessary and potentially counterproductive. 4, 1

• HRIG is contraindicated in previously vaccinated persons because it can actually suppress the anamnestic antibody response that develops rapidly after booster vaccination. 4, 1, 2
• Studies demonstrate that previously vaccinated individuals show robust antibody responses by day 7 after booster doses, regardless of the time elapsed since initial vaccination. 2

Complete Treatment Protocol

Immediate Wound Management (Critical First Step)

• Thoroughly wash the wound with soap and water for at least 15 minutes—this is the single most effective measure for reducing viral load and preventing rabies infection. 1, 2
• Apply povidone-iodine solution or another virucidal agent to the wound site if available. 1, 5, 2
• Avoid suturing the wound when possible to prevent deeper viral inoculation. 2
• Administer tetanus toxoid booster if indicated by immunization history. 5, 2
• Consider antibiotic prophylaxis based on wound characteristics (category III bites have significant infection risk). 2

Vaccination Schedule

• Administer 1.0 mL rabies vaccine (HDCV or PCECV) intramuscularly on day 0 (immediately) and day 3. 4, 1, 2, 3
• Inject in the deltoid muscle—never use the gluteal area, which produces inadequate antibody response and has been associated with vaccine failures. 1, 2, 3
• Day 0 is defined as the day the first dose is administered, not necessarily the day of exposure. 1

What NOT to Do (Critical Pitfalls)

• Do NOT administer HRIG—this is explicitly contraindicated in previously vaccinated persons and will inhibit the protective anamnestic response. 4, 1, 2, 3
• Do NOT use the 4-dose or 5-dose schedule intended for unvaccinated persons. 2
• Do NOT delay treatment while attempting to locate or test the animal—this is a medical urgency requiring immediate initiation. 5, 2

Special Considerations

If Immunocompromised

If this patient is immunosuppressed (by disease or medications such as corticosteroids, chemotherapy, or has HIV/AIDS), the recommendation changes completely:

• He would require the full 5-dose vaccine regimen (days 0,3,7,14, and 28) plus HRIG at 20 IU/kg on day 0, even with his prior vaccination history. 1, 2
• Mandatory serologic testing 1-2 weeks after the final dose would be required to confirm adequate antibody response. 1, 2

However, the question states "no known comorbidity," so the standard 2-dose regimen for previously vaccinated immunocompetent persons applies. 4, 1, 2

Timing Considerations

• Begin treatment immediately—rabies incubation periods can exceed 1 year, and even delayed treatment is indicated when exposure is recognized. 1, 5, 2
• Small delays of a few days between the two vaccine doses do not compromise protection. 1

Evidence Supporting This Approach

• The Advisory Committee on Immunization Practices (ACIP) explicitly states that persons who have previously received complete vaccination regimens should receive only vaccine without HRIG. 4
• The World Health Organization updated recommendations specifically streamline this to a 2-dose schedule (days 0 and 3) for previously vaccinated immunocompetent persons. 2
• When administered promptly and appropriately, this regimen is nearly 100% effective in preventing clinical rabies in previously vaccinated individuals. 1

Animal Observation Option

• If the animal is available and healthy, it can be observed for 10 days. 2
• If the animal remains healthy for 10 days or tests negative for rabies, prophylaxis can be discontinued. 2
• However, do not delay initiating the 2-dose vaccine series while waiting for observation results—begin immediately and discontinue only if the animal is proven rabies-free. 5, 2