What is the post-exposure prophylaxis (PEP) treatment for rabies?

Rabies Post-Exposure Prophylaxis (PEP)

For previously unvaccinated individuals exposed to rabies, immediately initiate a 4-dose rabies vaccine series (days 0,3,7,14) combined with human rabies immune globulin (HRIG) at 20 IU/kg infiltrated around the wound on day 0, along with thorough wound cleansing—this regimen is nearly 100% effective when properly administered. 1, 2

Immediate Wound Management (Critical First Step)

• Wash all bite wounds and scratches immediately and thoroughly with soap and water for approximately 15 minutes—this single intervention markedly reduces rabies risk in animal studies and is perhaps the most effective measure for preventing rabies 1, 2, 3
• Irrigate with a virucidal agent such as povidone-iodine solution if available 1, 2
• Administer tetanus prophylaxis and antibiotics as indicated for bacterial infection control 1, 2
• Avoid suturing wounds when possible to allow drainage 1

Post-Exposure Prophylaxis for Previously Unvaccinated Persons

Passive Immunization (HRIG)

• Administer HRIG at exactly 20 IU/kg body weight as a single dose on day 0 2, 4
• Infiltrate the full dose thoroughly around and into all wounds if anatomically feasible; inject any remaining volume intramuscularly at a site distant from the vaccine injection 1, 2
• HRIG can be administered through day 7 after the first vaccine dose; beyond day 7, it is not indicated since an antibody response to vaccine is presumed to have occurred 1, 3
• Never administer HRIG and vaccine in the same anatomical site 2

Active Immunization (Vaccine)

• Administer rabies vaccine (HDCV, PCECV, or RVA) as a 4-dose series on days 0,3,7, and 14 1, 2
• This updated 4-dose regimen replaced the previous 5-dose schedule in 2010 based on immunogenicity studies demonstrating adequate antibody response 1
• Inject vaccine intramuscularly in the deltoid muscle for adults and older children; use the anterolateral thigh for infants and small children 2, 4
• Never administer vaccine in the gluteal area—this results in lower neutralizing antibody titers 2

Post-Exposure Prophylaxis for Previously Vaccinated Persons

• Administer only 2 doses of rabies vaccine on days 0 and 3—no HRIG is needed 5, 6, 2
• Do not give HRIG to previously vaccinated individuals as it may blunt the rapid anamnestic antibody response 5, 2
• Previously vaccinated persons develop rapid anamnestic immune responses with adequate protective antibody titers 5
• This applies to anyone who has ever received a complete pre-exposure or post-exposure vaccination regimen with cell culture vaccine 1, 4

Timing and Urgency Considerations

• PEP is a medical urgency, not a medical emergency—initiate as soon as possible but decisions need not be delayed for consultation 1, 6
• Administer PEP regardless of delay, even months or years after exposure, provided the exposed person shows no clinical signs of rabies 1, 6, 2
• Incubation periods exceeding 1 year have been documented in humans, making delayed treatment still effective 1, 6
• If the animal is available for testing and tests negative by direct fluorescent antibody test, PEP can be discontinued 1, 4

Special Populations

Immunosuppressed Patients

• Administer the full 5-dose vaccination regimen (days 0,3,7,14,28) with HRIG for immunosuppressed individuals receiving post-exposure prophylaxis 5
• Consider checking rabies virus neutralizing antibody titers after completing the series 4

Animal Observation Protocol

• For healthy dogs, cats, or ferrets that bite a person, observe the animal for 10 days 6, 4, 3
• If the animal dies or is killed before completing the 10-day observation period, immediately initiate PEP—the observation period is prospective, not retrospective 6
• Begin PEP at the first sign of rabies in the observed animal 4, 3

High-Risk Exposures Requiring Immediate PEP

• Any bite or non-bite exposure from bats, skunks, raccoons, foxes, coyotes, or other wild carnivores—regard as rabid unless proven negative by laboratory testing 4, 3
• Any physical contact with bats when bite or mucous membrane contact cannot be excluded—bat bites may be less severe and go completely undetected 3
• Bites from rabid or suspected rabid dogs and cats 4, 3
• Non-bite exposures: scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or potentially infectious material (such as brain tissue) from a rabid animal 3

Efficacy and Safety

• The combination of wound care, HRIG, and vaccine is nearly 100% effective when properly administered 2, 7, 8
• No failures have been documented in the United States since current cell culture biologics were licensed, despite occasional improper administration 1, 2
• Worldwide, WHO estimates that PEP is initiated on 10-12 million persons annually 1
• Approximately 16,000-39,000 persons in the United States receive full post-exposure prophylaxis each year 1

Critical Pitfalls to Avoid

• Never delay PEP waiting for animal test results if the exposure involves high-risk species (bats, wild carnivores) 6, 4
• Do not give HRIG to previously vaccinated persons—it interferes with anamnestic response 5, 2
• Do not inject vaccine in gluteal region—inadequate antibody response 2
• Do not administer HRIG after day 7 of the vaccine series—unnecessary and potentially harmful 1, 3
• Do not assume casual contact (petting, contact with blood/urine/feces) constitutes exposure—these do not require prophylaxis 3

When PEP is NOT Indicated

• Casual contact such as petting a rabid animal 3
• Contact with blood, urine, or feces (including bat guano) of a rabid animal 3
• Exposure to dried material containing virus—the virus is considered noninfectious when dry 3
• Bites from squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, mice, other small rodents, rabbits, and hares in most geographical areas—these almost never require PEP 3