Antirabies%25252525252525252525252525252525252525252525252525252525252525252520vaccine

# Antirabies vaccine ## Overview Rabies vaccine is used for post-exposure prophylaxis (PEP) to prevent rabies infection following potential exposure to the rabies virus. It is also used for pre-exposure prophylaxis (PrEP) in individuals at high risk of exposure. ## Primary Indications * Post-exposure prophylaxis (PEP) after potential rabies virus exposure. * Pre-exposure prophylaxis (PrEP) for individuals with ongoing or anticipated occupational or recreational exposure risk. ## Adult Dosing **Post-Exposure Prophylaxis (PEP) - Unvaccinated or Incompletely Vaccinated Individuals:** * **Intramuscular (IM) Rabies Vaccine (HDCV, RFFV, or PVRV):** 1 mL IM on days 0, 3, 7, 14, and 28. * **Rabies Immune Globulin (RIG):** 20 IU/kg body weight infiltrated around the wound(s) on day 0. If infiltration is not possible, it can be given IM at a different site from the vaccine. **Post-Exposure Prophylaxis (PEP) - Previously Vaccinated Individuals (completed a full course of rabies vaccine):** * **IM Rabies Vaccine:** 1 mL IM on days 0 and 3. * **RIG:** Not indicated. **Pre-Exposure Prophylaxis (PrEP):** * **IM Rabies Vaccine:** 1 mL IM on days 0, 7, and 21 or 28. ## Pediatric Dosing **Post-Exposure Prophylaxis (PEP) - Unvaccinated or Incompletely Vaccinated Individuals:** * **IM Rabies Vaccine (HDCV, RFFV, or PVRV):** 1 mL IM on days 0, 3, 7, 14, and 28. * **Rabies Immune Globulin (RIG):** 20 IU/kg body weight infiltrated around the wound(s) on day 0. If infiltration is not possible, it can be given IM at a different site from the vaccine. (Dose may need to be adjusted based on weight to ensure adequate coverage). **Post-Exposure Prophylaxis (PEP) - Previously Vaccinated Individuals (completed a full course of rabies vaccine):** * **IM Rabies Vaccine:** 1 mL IM on days 0 and 3. * **RIG:** Not indicated. **Pre-Exposure Prophylaxis (PrEP):** * **IM Rabies Vaccine:** 1 mL IM on days 0, 7, and 21 or 28. ## Dose Adjustments No dose adjustments are typically required for renal or hepatic impairment. Dose of RIG may need to be adjusted based on weight in pediatric patients. ## Contraindications * Severe, life-threatening allergic reaction (anaphylaxis) to a previous dose of rabies vaccine or any component of the vaccine. * Severe allergic reaction to egg or gelatin if using a vaccine derived from these sources (e.g., HDCV, PVRV). ## Adverse Effects Common: * Local reactions at injection site (pain, redness, swelling, itching). * Systemic reactions (headache, dizziness, nausea, abdominal pain, muscle aches, joint pain, low-grade fever). Less Common/Rare: * Anaphylaxis. * Neurologic events (e.g., encephalitis, transverse myelitis, Guillain-Barré syndrome) have been rarely reported, particularly with older vaccine formulations. ## Key Drug Interactions * **Immunosuppressive Medications:** May reduce the immune response to rabies vaccine. If unavoidable, serologic testing to confirm adequate antibody levels may be considered. * **Corticosteroids (high dose or long-term):** May also impair the immune response. * **Chloroquine:** May interfere with the antibody response to rabies vaccine. Post-exposure prophylaxis should still be administered, but serologic testing is recommended to confirm adequate antibody levels. ## Monitoring * Monitor for adverse reactions following vaccination. * For individuals receiving PEP who are immunosuppressed or where there is doubt about adequate response, serologic testing for rabies virus neutralizing antibody (VNA) titers may be considered approximately 2-4 weeks after completion of vaccination. A VNA titer of at least 1:5 (median tissue culture infectious dose [TCID50]) is generally considered protective. ## Clinical Pearls * The decision to administer PEP should be based on the nature of the exposure, the species of animal, the availability of the animal for testing, and the prevalence of rabies in the geographic area. * RIG should be administered on day 0 with the first vaccine dose whenever possible. * RIG is not administered to individuals who have previously completed a full course of rabies vaccine. * If a dose of vaccine is missed, resume the schedule as soon as possible. The exact timing between doses is less critical than completing the series. *** **Disclaimer:** This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the most current prescribing information and relevant guidelines for specific patient management decisions.