Antirabies%25252525252525252525252525252525252525252525252525252525252520vaccine

# Antirabies vaccine ## Overview Rabies vaccine is an inactivated virus vaccine that stimulates the immune system to produce antibodies against the rabies virus. It is used for pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP). ## Primary Indications * **Pre-exposure prophylaxis (PrEP):** For individuals at high risk of exposure to rabies virus, such as veterinarians, animal handlers, laboratory workers, and travelers to rabies-endemic areas. * **Post-exposure prophylaxis (PEP):** For individuals who have been bitten or scratched by an animal suspected of having rabies or who have had mucous membrane contact with saliva from such an animal. ## Adult Dosing **Pre-exposure Prophylaxis (PrEP):** * Intramuscular (IM): 1 mL on days 0, 7, and 21 (or 28). * Intradermal (ID): 0.1 mL per site on days 0, 7, and 21 (or 28). Two sites on day 0 (e.g., deltoid area on each arm), one site on day 7, and one site on day 21 (or 28). ID route requires experienced administration and is generally not preferred in immunocompromised individuals or those with limited access to follow-up. **Post-exposure Prophylaxis (PEP) - Unvaccinated Individuals:** * Rabies Immune Globulin (RIG): 20 international units (IU)/kg body weight, infiltrated around the wound(s) and/or IM at a site distant from vaccine administration. Administer on day 0. * Rabies Vaccine: Four 1 mL IM doses on days 0, 3, 7, and 14. * **Alternative PEP (for those NOT treated with RIG on day 0):** Two 1 mL IM doses on day 0, followed by one 1 mL IM dose on days 7 and 14. (This alternative is not recommended by all guidelines, consult local protocol). **Post-exposure Prophylaxis (PEP) - Previously Vaccinated Individuals (with a completed primary series):** * No RIG. * Rabies Vaccine: Two 1 mL IM doses on days 0 and 3. ## Pediatric Dosing Dosing is weight-based for RIG. Vaccine volumes are the same as adults: * **RIG:** 20 IU/kg body weight. The total volume of RIG should be infiltrated as much as possible into the wound(s). Any remainder should be given IM at a site distant from vaccine administration. * **Rabies Vaccine:** 1 mL IM doses for children and infants. ## Dose Adjustments No dose adjustments are typically required based on renal or hepatic impairment. Immunosuppressed individuals may require a modified PrEP or PEP regimen which can depend on local protocols and expert consultation. ## Contraindications * Severe allergic reaction (anaphylaxis) to a previous dose of rabies vaccine or its components (e.g., neomycin, gelatin). * Acute febrile illness: Vaccination should be postponed until resolution of the illness. ## Adverse Effects **Common:** Pain, redness, swelling, itching at the injection site; headache, nausea, muscle aches, dizziness, abdominal pain. **Serious (rare):** Anaphylaxis, neurological complications (e.g., encephalitis, myelitis) although causality between vaccine and these events is often unproven. ## Key Drug Interactions * **Corticosteroids and other immunosuppressants:** May reduce the immune response to the vaccine. Consider antibody titers to assess immune status. * **Antimalarial drugs (e.g., chloroquine):** May interfere with the immune response to ID rabies vaccine. If using ID vaccination, antimalarials should be discontinued 1 week before vaccination and resumed 1 week after completion of the series. This interaction is not established for IM administration. ## Monitoring * **PEP:** Monitor for signs of rabies virus exposure and potential illness. Review vaccination history. * **PrEP:** Generally, no routine monitoring is required. Antibody titers are not routinely recommended after PrEP unless the individual is immunocompromised or has a potential exposure requiring PEP. ## Clinical Pearls * RIG should be administered as soon as possible after exposure, ideally along with the first dose of vaccine. * RIG should not be administered IM at the same site as vaccine in the same syringe. * The IM route is preferred for vaccine administration in PEP. * For PrEP, if the 21-day schedule is not completed, the series should be completed as soon as possible. If the 28-day schedule is not completed, additional doses may be needed. Consult CDC or WHO guidelines. * In individuals who are immunocompromised, PEP typically involves RIG and a longer vaccine series (e.g., five doses on days 0, 3, 7, 14, and 28). *** **Educational Disclaimer:** This information is intended for healthcare professionals. Always consult the most current official prescribing information and relevant clinical guidelines from the Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), or local health authorities before making prescribing decisions. Dosing and recommendations may vary based on product specifics and evolving clinical evidence.