From the Guidelines
Post-exposure prophylaxis (PEP) for rabies should be initiated as soon as possible after exposure, ideally on the same day, referred to as day 0, with the first dose of vaccine administered immediately. The timeframe to begin PEP is crucial, and it is recommended to start the treatment as soon as possible after exposure, as the risk of developing rabies increases with delay 1. The complete rabies PEP regimen consists of:
- Wound cleansing with soap and water for at least 15 minutes
- Rabies immune globulin (RIG) for previously unvaccinated individuals
- A series of rabies vaccines, with the first dose administered on day 0 For previously unvaccinated individuals, the standard regimen includes human rabies immune globulin (HRIG) at 20 IU/kg body weight infiltrated around the wound (with any remaining volume administered intramuscularly) and a series of four rabies vaccine doses given on days 0,3,7, and 14 1. For previously vaccinated individuals, only two doses of vaccine are needed (days 0 and 3), and RIG is not necessary 1. The urgency of PEP is based on the pathophysiology of rabies virus, which travels through peripheral nerves to the central nervous system at varying rates depending on the proximity of the bite to the head and the severity of exposure. Prompt initiation of PEP is essential to prevent the development of rabies, which is almost always fatal once symptoms develop 1.
From the FDA Drug Label
The sooner treatment is begun after exposure, the better If initiation of treatment is delayed for any reason, still administer Imogam Rabies – HT and the first dose of vaccine, regardless of the interval between exposure and treatment. If Rabies Immune Globulin (Human) was not administered when vaccination was begun (i. e., day 0), it can be administered up to and including day 7 of the post-exposure prophylaxis series.
The timeframe to begin post-exposure prophylaxis (PEP) for rabies exposure is as soon as possible after exposure. Immediate treatment is recommended, and it is crucial to start PEP promptly. If there is a delay in initiating treatment, PEP should still be administered, regardless of the time interval between exposure and treatment. Additionally, if Rabies Immune Globulin (Human) was not given on the first day of vaccination, it can be administered up to 7 days after the start of the vaccination series 2.
From the Research
Timeframe to Begin PEP for Rabies Exposure
- The timeframe to begin Post-Exposure Prophylaxis (PEP) for rabies exposure is as soon as possible after a high-risk exposure 3.
- According to the Centers for Disease Control and Prevention (CDC) guidelines, PEP should be given to persons exposed to index cases of rabies regardless of the length of delay 3.
- A study published in 2019 found that abridged vaccination schedules with less doses can be effective in preventing rabies, and the 1-week, 2-site ID PEP schedule was found to be most advantageous 4.
- Another study published in 2020 evaluated adherence to CDC recommendations for rabies immune globulin patient selection, dosing, timing, and anatomical site of administration, and found high adherence to guideline recommendations for rabies IG patient selection, dosing, and timing 5.
- The World Health Organization (WHO) recommends that PEP should be started as soon as possible after exposure, and that the first dose of vaccine should be given as soon as possible after exposure, followed by additional doses on days 3,7,14, and 28 4.
- A study published in 2022 found that human rabies immunoglobulin (HRIG) is safe and effective in preventing rabies when administered promptly after exposure, and that all study subjects were healthy and alive after 6 months following the administration of HRIG, along with a full course of anti-rabies vaccine 6.
- Overall, the evidence suggests that PEP for rabies exposure should be started as soon as possible after exposure, and that prompt administration of HRIG and vaccination can be effective in preventing rabies 3, 4, 6, 5.