Antirabies%25252525252525252525252525252525252525252525252525252520vaccine

# Antirabies vaccine ## Overview Antirabies vaccine is an inactivated vaccine that stimulates the immune system to produce antibodies against the rabies virus. Rabies is a viral disease that affects the central nervous system and is almost always fatal once symptoms appear. Post-exposure prophylaxis (PEP) is highly effective in preventing rabies. ## Primary Indications * **Post-exposure prophylaxis (PEP)** following potential rabies virus exposure from animal bites or other contact with rabid or potentially rabid animals. * **Pre-exposure prophylaxis (PrEP)** for individuals at high risk of rabies exposure. ## Adult Dosing **Post-Exposure Prophylaxis (PEP) - Unvaccinated Individuals:** * **Intramuscular (IM):** 4 doses of 1 mL each, given on days 0, 3, 7, and 14. * **Intramuscular (IM) with Rabies Immune Globulin (RIG):** 4 doses of 1 mL each, given on days 0, 3, 7, and 14. RIG is administered on day 0 only. **Post-Exposure Prophylaxis (PEP) - Previously Vaccinated Individuals:** * **Intramuscular (IM):** 2 doses of 1 mL each, given on days 0 and 3. RIG is NOT recommended. **Pre-Exposure Prophylaxis (PrEP):** * **Intramuscular (IM):** 3 doses of 1 mL each, given on days 0, 7, and 21 or 28. * **Intradermal (ID):** 2 doses (0.1 mL each) given on day 0, and 1 dose (0.1 mL) given on day 7. This is an alternative regimen for PrEP in some regions and requires careful technique. *Dosing for PEP may vary based on the specifics of the exposure and local public health protocols.* ## Pediatric Dosing Pediatric dosing is the same as adult dosing on a per-kilogram basis (1 mL per dose for IM). **Post-Exposure Prophylaxis (PEP) - Unvaccinated Children:** * **Intramuscular (IM):** 4 doses of 1 mL each, given on days 0, 3, 7, and 14. * **Intramuscular (IM) with Rabies Immune Globulin (RIG):** 4 doses of 1 mL each, given on days 0, 3, 7, and 14. RIG is administered on day 0 only. **Post-Exposure Prophylaxis (PEP) - Previously Vaccinated Children:** * **Intramuscular (IM):** 2 doses of 1 mL each, given on days 0 and 3. RIG is NOT recommended. **Pre-Exposure Prophylaxis (PrEP):** * **Intramuscular (IM):** 3 doses of 1 mL each, given on days 0, 7, and 21 or 28. * **Intradermal (ID):** Regimens are the same as adults. ## Dose Adjustments No dose adjustments are typically required for renal or hepatic impairment. ## Contraindications * Known severe allergic reaction (anaphylaxis) to previous doses of antirabies vaccine or any component of the vaccine, including neomycin, albumin, or gelatin (depending on vaccine formulation). * Severe febrile illness may warrant deferral of vaccination until recovery, but do not delay PEP due to a mild illness. ## Adverse Effects * **Common:** Local reactions at injection site (pain, redness, swelling, itching), mild fever, headache, muscle aches. * **Less Common:** Hives, joint pain, dizziness, nausea. * **Rare:** Anaphylaxis, neurological events (very rare and often difficult to attribute causally). ## Key Drug Interactions * **Immunosuppressive agents:** Corticosteroids, chemotherapy, other immunosuppressants may reduce the immune response to the vaccine. If a patient is on chronic immunosuppressive therapy, consider serologic testing to confirm adequate antibody response after vaccination. * **Antimalarials:** Chloroquine and hydroxychloroquine may interfere with the immune response to PEP. If a patient is receiving these medications, PEP should be given IM and not ID. ## Monitoring * **PEP:** Assess for signs and symptoms of rabies exposure. Monitor for adverse reactions to the vaccine. Serologic testing is generally not required for PEP if the vaccine regimen is completed as recommended. * **PrEP:** Antibody titers may be checked periodically to confirm sustained immunity, especially for individuals with ongoing high risk. ## Clinical Pearls * Rabies immune globulin (RIG) should be infiltrated around the wound site as much as possible on day 0 for unvaccinated individuals receiving PEP. If infiltration is not possible, administer IM. * RIG is not necessary for individuals who have been previously vaccinated. * PEP should be initiated as soon as possible after exposure. * Consult local public health authorities for guidance on animal assessment at the time of exposure, as this can sometimes alter the need for PEP. * The intradermal (ID) route for PrEP is an option in some regions, but requires careful administration and specific training. It is not typically used for PEP. *** **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 local guidelines for definitive drug management. Dosages and recommendations may change, and individual patient factors must be considered.