Antirabies%252525252525252520vaccine

# Antirabies Vaccine ## Overview Antirabies vaccines are inactivated virus preparations used for pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP). Current products in the U.S. include Human Diploid Cell Vaccine (HDCV) and Purified Chick Embryo Cell Vaccine (PCECV). ## Primary Indications * **Pre-exposure prophylaxis:** For high-risk individuals (e.g., veterinarians, animal handlers, high-risk laboratory workers, travelers to endemic areas). * **Post-exposure prophylaxis (PEP):** For individuals exposed to animals suspected or confirmed to have rabies. Must be administered in conjunction with local wound care and, for severe exposures, Rabies Immune Globulin (RIG). ## Adult Dosing * **Pre-exposure:** 1 mL IM (deltoid) on days 0 and 7. * **Post-exposure (previously unvaccinated):** 1 mL IM on days 0, 3, 7, and 14. * **Post-exposure (previously vaccinated):** 1 mL IM on days 0 and 3. RIG is typically not indicated. ## Pediatric Dosing * **Pre-exposure:** 1 mL IM (deltoid in older children; anterolateral thigh in infants/toddlers) on days 0 and 7. * **Post-exposure (previously unvaccinated):** 1 mL IM on days 0, 3, 7, and 14. * **Post-exposure (previously vaccinated):** 1 mL IM on days 0 and 3. * *Note: Never administer in the gluteal region, as this may result in lower neutralizing antibody titers.* ## Dose Adjustments * **Immunocompromised patients:** For PEP, a 5th dose on day 28 is recommended. Serologic testing is required 1–2 weeks after completing the series to confirm seroconversion. * **Renal/Hepatic:** No specific adjustments defined. ## Contraindications * **Pre-exposure:** History of severe allergic reaction (anaphylaxis) to a previous dose or vaccine component. * **Post-exposure:** There are **no** contraindications to PEP. If a significant exposure has occurred, the risk of rabies (which is universally fatal) outweighs the risk of anaphylaxis. Manage reactions with epinephrine and antihistamines. ## Adverse Effects * **Local:** Pain, erythema, swelling, or pruritus at the injection site (common). * **Systemic:** Mild flu-like symptoms, headache, fever, malaise, or nausea. * **Rare:** Serum sickness-like reactions (type III hypersensitivity), particularly with booster doses. ## Key Drug Interactions * **Immunosuppressants/Corticosteroids:** May interfere with the development of an active immune response. Avoid if possible during the vaccine series; if unavoidable, serologic testing for rabies antibodies is essential. * **Chloroquine:** May decrease the antibody response; if possible, avoid or use non-chloroquine antimalarials during the vaccine series. ## Monitoring * **Efficacy:** Not required for immunocompetent individuals. Mandatory for immunocompromised individuals, usually 1–2 weeks after the final vaccine dose, to ensure titers are adequate. * **Safety:** Monitor for signs of immediate hypersensitivity for 15–20 minutes post-injection. ## Clinical Pearls * **Wound Care:** Thorough scrubbing/flushing of the wound with soap and water or antiseptic is essential and significantly reduces risk. * **Protocol Variation:** PEP protocols vary globally (e.g., WHO guidelines vs. CDC guidelines, intradermal vs. intramuscular). **Always consult local health department guidelines and the current CDC *Morbidity and Mortality Weekly Report (MMWR)* regarding rabies prevention, as regimens are subject to change based on the specific product and clinical circumstances.** * **Administration:** Ensure IM injection into the deltoid or anterolateral thigh; avoid the gluteal muscle. *** **Educational Disclaimer:** This information is for educational purposes only. Rabies protocols are time-sensitive and highly dependent on local public health guidance and the specific vaccine product used. Always verify current prescribing information, package inserts, and official CDC guidelines before administration.