What is the recommended treatment for rabies exposure using Rabies Immune Globulin (RIG) (rabies human monoclonal antibodies)?

Rabies Post-Exposure Prophylaxis with Rabies Immune Globulin

For previously unvaccinated individuals exposed to rabies, administer rabies immune globulin (RIG) at 20 IU/kg body weight once at the beginning of post-exposure prophylaxis, infiltrating the full dose into and around the wound site when anatomically feasible, combined with a series of rabies vaccine doses. 1, 2, 3

Essential Components of Post-Exposure Prophylaxis

Immediate Wound Management

• Thoroughly wash all bite wounds and scratches immediately with soap and water for approximately 15 minutes. 1, 3
• Apply a virucidal agent such as povidone-iodine solution to the wound site. 1
• Administer tetanus prophylaxis and antibacterial measures as indicated. 1, 3

Rabies Immune Globulin Administration

Dosing:

• The standard dose is 20 IU/kg body weight for all age groups, including children. 1, 2, 3
• This dose applies to both human RIG (HRIG) and equine RIG (ERIG). 2

Timing:

• RIG is administered only once at the beginning of antirabies prophylaxis. 1, 2
• If not given initially, RIG can still be administered through day 7 after the first vaccine dose. 1, 2
• Beyond day 7, RIG is not indicated because an antibody response to the vaccine is presumed to have occurred. 1, 2

Administration Technique:

• Infiltrate the full calculated dose thoroughly into the area around and into the wounds when anatomically feasible. 1, 2, 3
• Any remaining volume should be injected intramuscularly at a site distant from vaccine administration. 1, 2
• This infiltration approach is critical—rare failures of post-exposure prophylaxis have occurred when smaller amounts were infiltrated at exposure sites. 1, 2

Critical Precautions

• Never administer RIG in the same syringe or at the same anatomical site as the vaccine. 1, 2
• Do not exceed the recommended dose, as RIG can partially suppress active antibody production from the vaccine. 1, 2

Vaccine Schedule for Previously Unvaccinated Persons

Standard Regimen:

• Administer five 1-mL doses of rabies vaccine (HDCV or PCECV) intramuscularly on days 0,3,7,14, and 28. 1
• For adults, always inject in the deltoid area; for children, the anterolateral thigh is also acceptable. 1
• Never use the gluteal area, as this results in lower neutralizing antibody titers. 1

Note: More recent guidelines have shifted to a 4-dose schedule for immunocompetent patients, with the 5-dose schedule reserved for immunocompromised individuals. 2

Previously Vaccinated Persons

• Individuals who have previously received complete rabies vaccination (pre-exposure or post-exposure with cell culture vaccine) require only vaccine—no RIG. 1, 2, 3
• These persons receive only 2 vaccine doses on days 0 and 3. 1, 2

Indications for Combined RIG and Vaccine

• The combination is recommended for both bite and non-bite exposures in previously unvaccinated persons, regardless of the interval between exposure and treatment initiation. 1, 2, 3
• Non-bite exposures include scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or brain tissue from a rabid animal. 3

Common Pitfalls to Avoid

• Failure to infiltrate RIG around the wound site has been associated with prophylaxis failures. 1, 2
• Administering vaccine in the gluteal area results in inadequate antibody response. 1
• Delaying treatment is dangerous—begin prophylaxis immediately, as incubation periods exceeding 1 year have been documented. 1
• Inadequate wound cleansing increases rabies risk, as thorough wound cleansing alone markedly reduces transmission likelihood. 1

Safety and Efficacy

• Field experience demonstrates that post-exposure prophylaxis combining wound treatment, RIG infiltration, and vaccination is uniformly effective when appropriately administered. 3
• A prospective study of 123 subjects receiving HRIG with full vaccination showed 11.4% incidence of mild adverse events (local pain, erythema, headache, fever), all resolving without complications, with 100% survival at 6 months. 4
• All persons tested 2-4 weeks after completing prophylaxis per ACIP guidelines have demonstrated antibody response. 1

Emerging Alternatives

Human monoclonal antibodies targeting rabies virus glycoprotein are under development as alternatives to traditional RIG, with some products receiving regulatory approval in India. 5, 6, 7 These offer advantages including consistent potency, unlimited supply potential, and broad neutralization of lyssavirus variants. 6, 7 However, traditional RIG remains the standard of care in the United States. 1, 2, 3