What is the administration protocol for the rabies vaccine (inactivated vaccines such as Imovax (rabies vaccine) or RabAvert (rabies vaccine)) in a human potentially exposed to rabies through an animal bite?

From the Guidelines

For a human potentially exposed to rabies through an animal bite, post-exposure prophylaxis (PEP) should be initiated immediately with a regimen consisting of both rabies immune globulin (RIG) and rabies vaccine. The vaccine (either Imovax or RabAvert) is administered as a series of 5 1-mL doses of HDCV or PCECV given intramuscularly on days 0,3,7,14, and 28 after exposure for previously unvaccinated persons 1. However, for persons who have ever previously received complete vaccination regimens with a cell culture vaccine, the recommendation is for only 2 doses of vaccine: one on day 0 and the second on day 3 1. Simultaneously with the first vaccine dose (day 0), human rabies immune globulin (HRIG) should be administered at 20 IU/kg body weight for previously unvaccinated persons, with as much HRIG as anatomically feasible infiltrated into and around the wound site, and any remaining volume injected intramuscularly at a site distant from the vaccine administration 1. This protocol is crucial because rabies is nearly always fatal once symptoms develop, and timely administration of PEP significantly improves outcomes 1. Key points to consider in the administration protocol include:

• Prompt and thorough wound cleansing
• Administration of HRIG and vaccine for previously unvaccinated persons
• Vaccine administration schedule based on previous vaccination history
• Importance of not delaying treatment while awaiting test results or observation of the animal.

From the FDA Drug Label

The essential components of rabies postexposure prophylaxis are prompt local treatment of wounds and administration of both HRIG and vaccine. A complete course of postexposure treatment for previously unvaccinated adults and children consists of a total of 5 doses of vaccine, each 1. 0 mL: one IM injection (deltoid) on each of Days 0,3,7,14, and 28. For previously immunized adults and children, a total of 2 doses of vaccine, each 1. 0 mL: one IM injection (deltoid) on each of Days 0 and 3.

Postexposure Prophylaxis of Rabies: The regimen for postexposure prophylaxis depends on whether or not the patient has been previously immunized against rabies (see below). For persons who have not previously been immunized against rabies, the schedule consists of an initial IM injection of HRIG exactly 20 IU/kg body weight in total If anatomically feasible, the FULL DOSE of HRIG should be thoroughly infiltrated in the area around and into the wounds. Any remaining volume of HRIG should be injected intramuscularly at a site distant from rabies vaccine administration. HRIG should never be administered in the same syringe or in the same anatomical site as the rabies vaccine HRIG is administered only once (for specific instructions for HRIG use, see the product package insert). The HRIG injection is followed by a series of 5 individual injections of RabAvert (1. 0 mL each) given intramuscularly on Days 0,3,7,14, and 28.

The administration protocol for the rabies vaccine in a human potentially exposed to rabies through an animal bite is as follows:

• Previously unvaccinated individuals: 5 doses of vaccine (1.0 mL each) given intramuscularly on Days 0,3,7,14, and 28, along with an initial injection of HRIG (20 IU/kg body weight) on Day 0.
• Previously immunized individuals: 2 doses of vaccine (1.0 mL each) given intramuscularly on Days 0 and 3, without HRIG. The vaccine should be administered in the deltoid muscle, and HRIG should be infiltrated into the wound area and injected intramuscularly at a distant site from the vaccine administration [ 2 ].

From the Research

Administration Protocol for Rabies Vaccine

The administration protocol for the rabies vaccine in a human potentially exposed to rabies through an animal bite involves several steps:

• Washing the wound with water and soap for 15 minutes 3
• Assessing the need for rabies biologicals based on specific criteria 3
• Administering, if required, rabies immunoglobulin or monoclonal antibodies deep in and around all wounds 3, 4
• Starting, if necessary, the WHO-recommended intradermal 1-week vaccination regimen 3, 5
• Informing patients adequately throughout the post-exposure prophylaxis (PEP) process to increase compliance and avoid dangerous misconceptions about animal bite treatment and rabies risk 3

Vaccine Administration

The intradermal 1-week vaccination regimen recommended by WHO is as safe as other regimens but carries important cost-, dose-, and time-sparing benefits 3, 5. The 1-week, 2-site ID PEP schedule is found to be most advantageous, as it is safe, immunogenic, supported by clinical outcome data, and involves the least direct costs compared to other schedules 5.

Post-Exposure Prophylaxis (PEP)

PEP consists of prompt and thorough wound cleansing and immunization with modern cell culture vaccine, together with administration of rabies immune globulin to those individuals who have not previously received preexposure prophylaxis 6. The volume of HRIG is calculated according to the body weight, and all the wounds are infiltrated as is anatomically feasible 4.

Safety and Efficacy

The human rabies immunoglobulin (HRIG) is a life-saving immune biological essential for all category III animal exposures, providing neutralizing antibodies at the site of exposure until the body can produce vaccine-mediated antibodies 4. The incidence of adverse events (AE) is mild and subsides without any complications 4. All study subjects were healthy and alive after 6 months following the administration of HRIG, along with a full course of anti-rabies vaccine 4.