What is the post-exposure prophylaxis (PEP) protocol for rabies, including the vaccination regimen and administration of rabies immune globulin (RIG)?

Rabies Post-Exposure Prophylaxis Protocol

The current recommended rabies post-exposure prophylaxis (PEP) protocol consists of thorough wound cleansing, administration of rabies immune globulin (RIG) at 20 IU/kg body weight (with as much as possible infiltrated around the wound), and a 4-dose vaccination regimen administered on days 0,3,7, and 14 for previously unvaccinated persons. 1

Components of Rabies PEP

1. Wound Treatment

• Immediately and thoroughly wash all bite wounds and scratches with soap and water for about 15 minutes 1, 2
• Use a virucidal agent such as povidone-iodine solution to irrigate the wounds when available 1
• Provide tetanus prophylaxis and measures to control bacterial infection as indicated 1, 2
• Consider cosmetic factors and potential for bacterial infections when deciding whether to suture large wounds 1

2. Rabies Immune Globulin (RIG) Administration

• Administer 20 IU/kg body weight of human rabies immune globulin (HRIG) 1
• If anatomically feasible, infiltrate the full dose around and into all wounds 1, 2
• Administer any remaining volume intramuscularly at a site distant from vaccine administration 1
• HRIG should never be administered in the same syringe or at the same anatomic site as the first vaccine dose 1
• HRIG is administered only once at the beginning of PEP, or up to day 7 if not given when vaccination was initiated 1

3. Vaccine Administration for Previously Unvaccinated Persons

• Administer 4 doses of 1 mL of human diploid cell vaccine (HDCV) or purified chick embryo cell vaccine (PCECV) intramuscularly 1
• Schedule: days 0 (first day of administration), 3,7, and 14 1
• For immunocompromised persons, administer 5 doses on days 0,3,7,14, and 28 1
• Administer vaccine in the deltoid area for adults and older children; anterolateral aspect of the thigh is acceptable for younger children 1
• Never administer vaccine in the gluteal area as it may result in diminished immune response 1

4. Protocol for Previously Vaccinated Persons

• For persons who have previously received complete rabies vaccination or have documented rabies antibody titers 1:
  • Administer 2 doses of vaccine (1 mL each, IM in deltoid) on days 0 and 3
  • Do not administer HRIG
  • Still perform thorough wound cleansing

Special Considerations

Animal Exposure Assessment

• Begin PEP immediately for exposures to wild animals like skunks, raccoons, foxes, and bats, unless the animal is available for testing 2
• For domestic dogs, cats, and ferrets that appear healthy and can be observed for 10 days, PEP may be delayed unless the animal develops signs of rabies 2
• Consult public health officials for guidance on exposures to other domestic animals 1

Types of Exposure

• Bite exposure: Any penetration of skin by teeth 2
• Non-bite exposure: Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or other potentially infectious material 2
• Indirect contact (petting an animal, contact with blood/urine/feces, or contact of saliva with intact skin) does not constitute exposure requiring PEP 2

Common Pitfalls and Caveats

• Delaying PEP: Rabies PEP should be initiated as soon as possible after exposure, though it is still indicated regardless of the time interval between exposure and treatment initiation 1
• Insufficient wound infiltration: Failure to thoroughly infiltrate HRIG around all wounds has been associated with rare PEP failures 1
• Improper injection site: Administering vaccine in the gluteal area results in lower antibody titers 1
• Incorrect HRIG dose: Using more than the recommended dose of HRIG may suppress active antibody production 1
• Incomplete vaccination: Every effort should be made to complete the full vaccination schedule, though minor delays in individual doses are not critical 1

The current 4-dose vaccine regimen (reduced from the previous 5-dose regimen) has been shown to be safe and effective while providing cost savings to the healthcare system 1. When properly administered, modern rabies PEP is virtually 100% effective in preventing this otherwise fatal disease 2, 3.