Antirabies%2520vaccine

# Antirabies Vaccine ## Overview Rabies vaccine is an inactivated virus preparation used for pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP). In the US, Human Diploid Cell Vaccine (HDCV) and Purified Chick Embryo Cell Vaccine (PCECV) are commonly used. ## Primary Indications * **Post-exposure Prophylaxis (PEP):** Individuals exposed to a rabid animal or animal suspected of having rabies. * **Pre-exposure Prophylaxis (PrEP):** Individuals at high risk of exposure (e.g., veterinarians, laboratory workers, cave explorers). ## Adult Dosing * **Post-exposure Prophylaxis:** * **Unvaccinated:** 1 mL IM on days 0, 3, 7, and 14. If immunocompromised, add a dose on day 28 (total of 5 doses). **Must** be co-administered with Rabies Immune Globulin (RIG) 20 IU/kg on day 0. * **Previously Vaccinated:** 1 mL IM on days 0 and 3. Do **not** administer RIG. * **Pre-exposure Prophylaxis:** 1 mL IM on days 0 and 7. ## Pediatric Dosing * **Dosing for children is identical to adults (1 mL IM).** * **PEP:** Days 0, 3, 7, and 14 (add day 28 for immunocompromised). * **RIG:** 20 IU/kg for PEP. Infiltrate as much of the dose as possible around the wound(s); administer the remainder IM at a site distant from the vaccine. ## Dose Adjustments * **Renal/Hepatic Impairment:** No adjustments required. * **Immunocompromised:** Must receive a 5th dose on day 28 for PEP. Serologic testing 1–2 weeks after the last dose is recommended to ensure seroconversion. ## Contraindications * **Pre-exposure:** History of severe allergic reaction (anaphylaxis) to a previous dose or vaccine component. * **Post-exposure:** There are **no absolute contraindications** for PEP because rabies is universally fatal. If a patient is allergic, monitor closely and manage hypersensitivity reactions with antihistamines or epinephrine. ## Adverse Effects * **Common:** Pain, redness, swelling, or induration at the injection site; headache, malaise, dizziness, or low-grade fever. * **Rare:** Serum sickness-like reactions (usually 5–15 days post-vaccination), anaphylactoid reactions, or systemic allergic responses. ## Key Drug Interactions * **Immunosuppressants/Corticosteroids:** May diminish the immune response to the vaccine. Avoid administration during PEP if possible; if necessary, ensure monitoring of rabies antibody titers. * **Rabies Immune Globulin (RIG):** Must be given simultaneously with the first dose of the vaccine series for PEP, but at a different anatomic site. ## Monitoring * **Post-exposure:** Monitor for signs of serum sickness reaction. For immunocompromised patients, check rabies neutralizing antibody titers 1–2 weeks after the completion of the series. * **Pre-exposure:** Routine booster doses are no longer recommended for most; check titers periodically only for those with high-risk, continuous exposure. ## Clinical Pearls * **Administration:** Administer IM only, preferably in the deltoid muscle (adults/older children) or the anterolateral thigh (infants/small children). Never inject into the gluteal region, as this may result in lower neutralizing antibody titers. * **Wound Care:** Crucial first step in PEP is aggressive cleaning of the wound with soap and water/antiseptic. * **Local Protocols:** Dosage schedules and availability may vary based on local public health guidelines (e.g., WHO vs. CDC protocols). Always consult the local health department or the CDC's latest Rabies guidance before initiating therapy. *** **Educational Disclaimer:** This information is for educational purposes only. Drug dosing, local health mandates, and clinical guidelines can change frequently. Always verify the most current prescribing information, state/local health department policies, and official CDC guidelines before prescribing or administering medications.