What is the appropriate management for a patient bitten by bats, regarding Rabies (Rabies virus) vaccination and administration of Rabies Immunoglobulin (RIG), considering prior vaccination status?

From the Guidelines

For any person with a potential rabies exposure who has not been previously vaccinated, post-exposure prophylaxis should include both rabies immune globulin (RIG) and the rabies vaccine series, with a reduced regimen of 4 doses of vaccine administered on days 0,3,7, and 14, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1. The RIG provides immediate passive immunity while the vaccine stimulates active immunity. The standard regimen includes RIG (20 IU/kg) administered at the wound site on day 0, along with the first dose of rabies vaccine. For previously vaccinated individuals, only the vaccine is needed, with a 2-dose regimen on days 0 and 3, without RIG, as an anamnestic response will follow the administration of a booster regardless of the prebooster antibody titer 1. Key considerations for management include:

• Prompt wound cleansing
• Administration of RIG for previously unvaccinated individuals
• Vaccination with a cell culture rabies vaccine
• Reporting to public health authorities, although this is not the primary clinical intervention needed Immediate post-exposure prophylaxis is critical as rabies is nearly 100% fatal once symptoms develop, making proper initial management essential. The most recent and highest quality study, from 2010, supports the use of a reduced 4-dose vaccine schedule for postexposure prophylaxis 1. This approach is based on evidence from rabies virus pathogenesis data, experimental animal work, clinical studies, and epidemiologic surveillance, which indicate that 4 vaccine doses in combination with RIG elicit adequate immune responses and that a fifth dose of vaccine does not contribute to more favorable outcomes.

From the FDA Drug Label

The essential components of rabies post-exposure prophylaxis are wound treatment and, for previously unvaccinated persons, the administration of both human rabies immune globulin (RIG) and vaccine. Post-exposure antirabies vaccination should always include administration of both passive antibody and vaccine, with the exception of persons who have ever previously received complete vaccination regimens (pre-exposure or post-exposure) with a cell culture vaccine or persons who have been vaccinated with other types of vaccines and have previously had a documented rabies virus neutralizing antibody titer. The combination of RIG and vaccine is recommended for both bite and nonbite exposures reported by persons who have never been previously vaccinated for rabies, regardless of the interval between exposure and initiation of prophylaxis When an immunized person who was vaccinated using the recommended pre-exposure regimen or a prior post-exposure regimen with a cell culture vaccine or who had previously demonstrated rabies antibody is exposed to rabies, that person should receive two intramuscular doses (1. 0 mL each) of Imovax Rabies vaccine, one dose immediately after the exposure and one dose 3 days later. RIG should not be given in these cases.

For a patient bitten by bats, regarding Rabies vaccination and administration of Rabies Immunoglobulin (RIG), considering prior vaccination status:

• Previously unvaccinated persons: should receive 5 intramuscular doses of Rabies vaccine and 20 IU/kg of RIG on Day 0.
• Previously vaccinated persons: should receive 2 intramuscular doses of Rabies vaccine, one dose immediately after the exposure and one dose 3 days later. RIG should not be given in these cases. Key considerations include:
• Wound treatment: thorough washing and flushing with soap and water, and application of a viricidal topical preparation if available.
• Urgency of treatment: the sooner treatment is begun after exposure, the better.
• Consultation with public health officials: may be necessary to determine the need for post-exposure prophylaxis and to guide management. 2 2

From the Research

Management of Bat Bites Regarding Rabies Vaccination and RIG Administration

• The management of patients bitten by bats, regarding Rabies (Rabies virus) vaccination and administration of Rabies Immunoglobulin (RIG), depends on the prior vaccination status of the individual 3.
• For individuals who have not been previously vaccinated against rabies, post-exposure prophylaxis (PEP) consists of a combination of wound cleansing, administration of the rabies vaccine, and administration of human rabies immune globulin (HRIG) 3, 4.
• The administration of HRIG provides neutralizing antibodies at the site of exposure until the body can produce vaccine-mediated antibodies 4.
• For individuals who have been previously vaccinated against rabies, the management may differ, but the exact approach is not specified in the provided studies.

Prior Vaccination Status Considerations

• Pre-exposure prophylaxis entails the administration of the rabies vaccine to individuals at high risk for exposure to rabies viruses, which may confer some protection from the virus while simplifying postexposure prophylaxis regimens 3.
• Postexposure prophylaxis regimens depend on the vaccination status of the victim, with previously vaccinated individuals potentially requiring a different approach than those who have not been vaccinated 3.

Administration of RIG and Vaccination

• The volume of HRIG should be calculated according to the body weight, and all wounds should be infiltrated as anatomically feasible 4, 5.
• The World Health Organization (WHO) recommends only infiltration of wounds without distal intramuscular injection for the administration of RIG 5.
• A full course of anti-rabies vaccination should be provided to all individuals exposed to bats, regardless of prior vaccination status 6, 4.