What is the post-exposure prophylaxis regimen for rabies, including the administration of rabies immunoglobulin and the rabies vaccine (Anti-Rabies Vaccine)?

Anti-Rabies Vaccine Post-Exposure Prophylaxis

Immediate Management

For previously unvaccinated individuals exposed to rabies, post-exposure prophylaxis (PEP) consists of immediate wound care, rabies immune globulin (RIG) at 20 IU/kg body weight infiltrated around the wound, and a 4-dose vaccine series on days 0,3,7, and 14. 1

Wound Care (Critical First Step)

• Immediately and thoroughly wash all bite wounds and scratches with soap and water for approximately 15 minutes - this alone markedly reduces rabies risk in animal studies 1, 2
• Irrigate wounds with a virucidal agent such as povidone-iodine solution if available 1
• Avoid suturing wounds when possible to prevent deeper contamination 3
• Administer tetanus prophylaxis and bacterial infection control measures as indicated 1, 4

Post-Exposure Prophylaxis Regimen

For Previously Unvaccinated Persons

Rabies Immune Globulin (RIG):

• Administer 20 IU/kg body weight once on day 0 1
• Infiltrate the full dose around and into the wound(s) if anatomically feasible - this is critical as failures have occurred when smaller amounts were infiltrated at exposure sites 1
• Inject any remaining volume intramuscularly at a site distant from vaccine administration 1
• Never administer RIG in the same syringe or anatomical site as the vaccine 1, 3
• RIG can be given up to day 7 after the first vaccine dose if not initially administered, but beyond day 7, RIG is not indicated as antibody response to vaccine is presumed to have occurred 1

Rabies Vaccine:

• Administer 4 doses of 1.0 mL intramuscularly on days 0,3,7, and 14 (updated from the older 5-dose regimen) 1
• Inject in the deltoid area for adults and older children; the anterolateral thigh is acceptable for younger children 1
• Never use the gluteal area as this results in lower neutralizing antibody titers 1
• Day 0 is the day the first vaccine dose is administered 1

For Previously Vaccinated Persons

• Administer vaccine only - no RIG 1, 5
• Give 2 doses of 1.0 mL intramuscularly on days 0 and 3 1
• This applies to anyone with prior complete pre-exposure or post-exposure vaccination with cell culture vaccine, or documented antibody response to prior vaccination 1

Special Considerations

Immunocompromised Patients

• Use the full 5-dose vaccine schedule on days 0,3,7,14, and 28 instead of the 4-dose regimen 1

Timing of PEP Initiation

• Begin PEP as soon as possible after exposure, ideally within 24 hours 4, 6
• However, PEP should be administered regardless of delay as long as clinical signs of rabies are not present, since incubation periods exceeding 1 year have been documented in humans 1, 5
• PEP is a "medical urgency, not a medical emergency" - it should be done promptly but is not too late even if delayed 5

Exposure Risk Assessment

High-Risk Exposures Requiring PEP:

• Any bite that penetrates the skin - bites to face and hands carry highest risk but site should not influence treatment decision 3, 4
• Bat exposures warrant special consideration: even minimal injury from bat bites may go undetected, so PEP should be considered for any physical contact with bats when bite or mucous membrane contact cannot be excluded 3
• Non-bite exposures: contamination of open wounds, abrasions, mucous membranes, or scratches with saliva or neural tissue from a rabid animal 1, 4

Low-Risk Exposures NOT Requiring PEP:

• Petting a rabid animal without wound contamination 4
• Contact with blood, urine, or feces of a rabid animal 3, 4
• Dried material containing virus (inactivated by desiccation) 3

Animal Observation Period:

• Healthy dogs, cats, or ferrets can be observed for 10 days - if the animal remains healthy throughout this period, PEP is not needed 5, 2
• If the animal dies, is killed, or shows signs of rabies before completing the 10-day observation, immediately initiate PEP 5
• The observation period is prospective, not retrospective - the animal must be alive and healthy throughout 5
• Wild animals (skunks, bats, foxes, coyotes, raccoons) should be regarded as rabid unless proven negative by laboratory testing 4

Critical Pitfalls to Avoid

• Do not delay wound washing - this is the single most important preventive measure 1, 2
• Do not exceed the recommended RIG dose as it can partially suppress active antibody production 1
• Do not administer RIG to previously vaccinated persons as it may blunt their rapid memory response 1, 3
• Do not use the gluteal area for vaccine injection due to reduced immunogenicity 1
• Do not withhold PEP for fully vaccinated pets if they died before completing the 10-day observation 5

Clinical Efficacy

• Modern cell culture vaccines with proper PEP are nearly 100% effective when administered correctly and promptly 6, 7
• No documented failures have occurred with modern cell culture vaccines when properly administered, even if started late 5
• Once clinical rabies develops, the disease is nearly 100% fatal - only seven individuals have survived rabies infection to date 6