Antirabies%25252525252525252525252525252525252525252520vaccine

# Antirabies Vaccine ## Overview Antirabies vaccine is used for pre-exposure prophylaxis and post-exposure prophylaxis (PEP) to prevent rabies infection. ## Primary Indications * **Pre-exposure prophylaxis (PrEP):** For individuals with increased risk of exposure to rabies virus (e.g., veterinarians, animal handlers, travelers to endemic areas). * **Post-exposure prophylaxis (PEP):** Following potential rabies virus exposure in conjunction with rabies immune globulin (RIG) for unvaccinated individuals, or without RIG for previously vaccinated individuals. ## Adult Dosing * **PrEP:** * Intramuscular (IM): 1 mL on days 0, 7, and 21 (or 28). A booster dose is not routinely recommended for immunocompetent individuals but may be considered based on continued risk or serologic testing. * Intradermal (ID): 0.1 mL at three different sites on days 0, 7, and 21 (or 28). This is an alternative regimen where locally available and cost-effective. * **PEP (Unvaccinated individuals):** * IM: 1 mL on days 0, 3, 7, 14, and 28. Administer RIG on day 0. * ID: 0.1 mL at two different sites on days 0, 3, 7, and 28. Administer RIG on day 0. * **PEP (Previously vaccinated individuals):** * IM: 1 mL on days 0 and 3. * ID: 0.1 mL at two different sites on days 0 and 3. * RIG is NOT indicated for previously vaccinated individuals. ## Pediatric Dosing Pediatric dosing is generally the same as adult dosing **by weight, not by age**. The standard 1 mL IM dose or 0.1 mL ID dose is used. ## Dose Adjustments No dose adjustments are needed for renal or hepatic impairment. Dose depends on exposure risk and vaccination history. ## Contraindications * Severe, life-threatening allergic reaction (anaphylaxis) to a previous dose of rabies vaccine or any component of the vaccine. * Severe (anaphylactic) hypersensitivity to components of the vaccine (e.g., neomycin, streptomycin, amphotericin B when used in production). ## Adverse Effects Common: Headache, fatigue, muscle aches, nausea, dizziness, abdominal pain, joint pain. Local reactions at the injection site (redness, swelling, pain, itching). Less Common: Hives, joint swelling, fever, enlarged lymph nodes. Rare: Severe allergic reactions. Neurologic events are exceedingly rare. ## Key Drug Interactions * **Immunosuppressants:** May reduce the immune response to rabies vaccine. If concurrent therapy is unavoidable, assess antibody titers and consider administering additional doses. Steroids >20 mg/day prednisone equivalent for >14 days can interfere. * **Antimalarials (e.g., chloroquine, mefloquine):** May reduce antibody response to intradermal rabies vaccine. IM vaccination should be used if antimalarials are necessary. ## Monitoring * **PrEP:** Antibody titers are not routinely required but can be considered to assess response, especially in immunocompromised individuals or those with ongoing risk. * **PEP:** Clinical assessment for signs and symptoms of rabies. Wound care. Documentation of vaccine and RIG administration. ## Clinical Pearls * Rabies vaccine is highly effective when administered correctly, but **rabies immune globulin (RIG) is crucial for unvaccinated individuals receiving PEP**. RIG should be infiltrated around the wound as much as possible and the remainder given intramuscularly. * Washing the wound thoroughly with soap and water is the **first and most critical step** in rabies PEP. * The choice between IM and ID administration for PEP may vary based on local protocols and resource availability. While ID offers potential cost savings, IM is generally considered more reliable. * Consult the most current CDC guidelines or local public health protocols for definitive recommendations on PEP, especially regarding the type of animal involved and its health status. *** **Disclaimer:** This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the current prescribing information and local protocols for definitive guidance.