What is the recommended post‑exposure prophylaxis for a person with a potential rabies exposure, including wound cleansing, rabies‑immune globulin (RIG) dosing, and the appropriate rabies vaccine schedule?

Rabies Post-Exposure Prophylaxis Protocol

For previously unvaccinated individuals with potential rabies exposure, immediately initiate a four-dose rabies vaccine series (days 0,3,7,14) combined with human rabies immune globulin (HRIG) 20 IU/kg on day 0, preceded by thorough wound cleansing with soap and water for 15 minutes. 1

Immediate Wound Management (First Priority)

• Wash all wounds thoroughly with soap and water for at least 15 minutes—this is the single most effective measure for preventing rabies infection and must be performed before any other intervention. 1, 2
• Follow wound washing with irrigation using a virucidal agent such as povidone-iodine solution if available. 1, 2
• Administer tetanus prophylaxis and antibiotics as indicated for bacterial infection control. 3, 4
• Avoid suturing large wounds when possible unless cosmetic factors or high risk of bacterial infection necessitate closure. 3, 4

Human Rabies Immune Globulin (HRIG) Administration

Dosing and Timing

• Administer HRIG at exactly 20 IU/kg body weight on day 0, ideally simultaneously with the first vaccine dose. 1, 2
• HRIG can be given up to and including day 7 after the first vaccine dose if not administered initially, but must not be given after day 7 because vaccine-induced antibodies are presumed to have developed. 1, 2

Infiltration Technique

• Infiltrate the full calculated dose around and into all wound(s) if anatomically feasible—this provides immediate passive immunity at the site where virus enters peripheral nerves. 1, 2
• Inject any remaining volume intramuscularly at a site distant from the vaccine administration site. 1, 2
• Never administer HRIG in the same syringe or at the same anatomical site as the vaccine, as this can interfere with vaccine efficacy. 1, 2

Critical Dosing Warning

• Do not exceed 20 IU/kg—higher doses partially suppress active antibody production from the vaccine and may compromise protection. 1, 2

Rabies Vaccine Administration

Standard Four-Dose Schedule (Immunocompetent Patients)

• Administer four intramuscular doses of 1.0 mL each on days 0,3,7, and 14 using human diploid cell vaccine (HDCV) or purified chick embryo cell vaccine (PCECV). 1, 5
• Day 0 is defined as the day the first dose is given, not necessarily the day of exposure. 1

Injection Site Selection

• Adults and older children: Inject in the deltoid muscle. 1, 2
• Young children and infants: Use the anterolateral aspect of the thigh. 1, 2
• Never use the gluteal area—this produces inadequate antibody response and has been associated with vaccine failures. 1, 2

Modified Regimens for Special Populations

Previously Vaccinated Persons

• Administer only 2 doses of vaccine on days 0 and 3—no HRIG is needed. 1, 2
• This applies to anyone who has completed a recommended pre-exposure or post-exposure vaccination series with a cell culture vaccine and has documented adequate antibody response. 1, 2
• Do not give HRIG to previously vaccinated persons—it will inhibit the anamnestic antibody response and is a critical error. 1

Immunocompromised Patients

• Use a five-dose vaccine regimen on days 0,3,7,14, and 28 plus HRIG at 20 IU/kg on day 0, even if previously vaccinated. 1, 2
• This applies to patients on corticosteroids, other immunosuppressive agents, antimalarials, or those with HIV, chronic lymphoproliferative leukemia, or other immunosuppressive illnesses. 1
• Mandatory serologic testing: Check rabies virus-neutralizing antibody by rapid fluorescent focus inhibition test (RFFIT) 1-2 weeks after the final vaccine dose. 1
• An acceptable response is complete neutralization at a 1:5 serum dilution. 1

Timing Considerations and Efficacy

• Initiate PEP as soon as possible after exposure, ideally within 24 hours, though treatment remains indicated even if weeks or months have elapsed since exposure. 1, 2
• There is no absolute cutoff for initiating PEP—rabies incubation periods can exceed one year, and the disease is uniformly fatal once symptoms appear. 1, 2
• When administered promptly and appropriately, this regimen is nearly 100% effective in preventing human rabies. 1
• No human rabies cases in the United States have been attributed to receiving the complete recommended PEP protocol since modern cell-culture vaccines were licensed. 1

Common Clinical Pitfalls to Avoid

• Do not delay treatment while waiting for animal observation or testing results—initiate PEP immediately in rabies-endemic areas and discontinue only if laboratory testing confirms the animal is not rabid. 2, 6
• Do not withhold PEP based on time elapsed since exposure—even years-old exposures warrant treatment if clinical rabies has not developed. 2
• Do not administer vaccine in the gluteal region—this is associated with inadequate immune response and treatment failures. 1, 2
• Do not give HRIG to previously vaccinated individuals—this suppresses the memory immune response. 1
• Do not exceed the 20 IU/kg HRIG dose—higher amounts suppress active antibody production. 1, 2
• Small delays of a few days between individual vaccine doses are unimportant and do not compromise protection, though longer lapses of weeks may warrant serologic testing. 1

Exposure Risk Assessment

• Bite exposures: Any penetration of skin by teeth constitutes a bite exposure requiring evaluation. 1
• Nonbite exposures: Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or neural tissue from a rabid animal also constitute exposure. 1, 6
• Non-exposures: Petting a rabid animal, contact with blood/urine/feces alone, or contact with dried infectious material does not warrant prophylaxis. 1, 6
• Bat exposures: Consider PEP for any physical contact with bats when bite or mucous membrane contact cannot be excluded, as bat bites may be less severe and go undetected. 6