What are the guidelines for rabies vaccination and post-exposure prophylaxis?

Rabies Vaccination and Post-Exposure Prophylaxis Guidelines

The current CDC recommendation for rabies post-exposure prophylaxis (PEP) consists of wound cleansing, human rabies immune globulin (HRIG) administration, and a 4-dose vaccine regimen administered on days 0,3,7, and 14 for previously unvaccinated individuals. 1

Wound Cleansing

Immediate and thorough wound cleansing is the first critical step in rabies PEP:

• Wash all wounds thoroughly with soap and water for at least 15 minutes
• If available, apply a virucidal agent (e.g., povidone-iodine solution) to irrigate the wounds 1, 2
• This step alone can markedly reduce the likelihood of rabies transmission 3

Post-Exposure Prophylaxis for Unvaccinated Persons

Human Rabies Immune Globulin (HRIG)

• Dose: 20 IU/kg body weight 1
• Administration:
  • If anatomically feasible, infiltrate the full dose around and into the wound(s)
  • Any remaining volume should be administered intramuscularly at a site distant from vaccine administration 1, 3
  • HRIG can be administered up to and including day 7 after the first vaccine dose 1
  • Never administer HRIG in the same syringe or at the same anatomical site as the vaccine 1

Vaccine Administration

• Regimen: 4 doses of Human Diploid Cell Vaccine (HDCV) or Purified Chick Embryo Cell Vaccine (PCECV)
• Dose: 1.0 mL per dose
• Schedule: Days 0,3,7, and 14 1
• Administration site:
  • Adults and older children: Deltoid area only
  • Young children: Anterolateral aspect of the thigh is acceptable
  • Never administer in the gluteal area (results in diminished immune response) 1, 2
• Special case: Immunocompromised individuals should receive 5 doses on days 0,3,7,14, and 28 1

Post-Exposure Prophylaxis for Previously Vaccinated Persons

For individuals who have previously received complete pre-exposure or post-exposure rabies vaccination:

• Wound cleansing: Same thorough cleansing as for unvaccinated persons
• HRIG: Not indicated
• Vaccine: 2 doses of HDCV or PCECV (1.0 mL each) administered on days 0 and 3 1

Animal Exposure Assessment

The need for PEP depends on several factors:

Animal Species and Condition

• Dogs, cats, and ferrets:

  • Healthy and available for 10-day observation: No PEP unless animal develops signs of rabies
  • Rabid or suspected rabid: Immediate PEP
  • Unknown/escaped: Consult public health officials 3, 4

• High-risk wildlife (skunks, raccoons, foxes, bats, and other carnivores):

  • Consider rabid unless proven negative by laboratory testing
  • Immediate PEP recommended 3, 4

• Low-risk animals (small rodents, rabbits):

  • Rarely require PEP; consult public health officials 3

Type of Exposure

• Bite exposure: Any penetration of skin by teeth
• Non-bite exposure: Scratches, abrasions, open wounds or mucous membranes contaminated with saliva or potentially infectious material 3
• Bat exposures: Consider PEP for any physical contact with bats when bite or mucous membrane contact cannot be excluded 3

Pre-Exposure Prophylaxis

Recommended for individuals at high risk of exposure:

• Laboratory workers handling rabies virus
• Veterinarians and staff
• Animal control and wildlife officers in endemic areas
• Individuals who frequently handle bats
• International travelers to endemic areas with limited access to medical care 2, 4

Pre-exposure regimen: 3 doses of 1.0 mL administered intramuscularly on days 0,7, and 21 or 28 2

Common Pitfalls and Caveats

1. Delayed initiation: PEP should be started as soon as possible after exposure, but there is no absolute time limit. Even with significant delays, PEP should still be administered if exposure is confirmed 2

2. Improper HRIG administration: Failure to properly infiltrate wounds with HRIG is a common error. The full dose should be infiltrated around and into the wound(s) if anatomically feasible 2, 5

3. Incorrect injection site: Using the gluteal area for vaccine administration results in diminished immune response 1

4. Incomplete vaccination: Failure to complete the full regimen reduces effectiveness 2

5. Inadequate wound cleansing: This critical first step is sometimes overlooked or performed inadequately 2

6. Unnecessary HRIG administration: Previously vaccinated individuals should not receive HRIG as it may inhibit the anamnestic response 1

7. Bat exposures: Some bat bites may be less severe or go undetected, requiring special consideration for PEP even when a definitive bite cannot be confirmed 3

Correctly administered PEP is nearly 100% effective in preventing rabies, which is almost invariably fatal once clinical symptoms appear 2.