Antirabies Vaccine

# Antirabies vaccine ## Overview - **Classification**: Vaccine, Inactivated - **Mechanism**: Induces active immunity by stimulating the production of neutralizing antibodies against the rabies virus. Contains inactivated rabies virus glycoprotein. ## Primary Indications 1. **Pre-exposure Prophylaxis (PrEP)**: For individuals at high risk of rabies exposure. 2. **Post-exposure Prophylaxis (PEP)**: For individuals potentially exposed to rabies virus. 3. **Pre-exposure Booster**: For individuals with prior PrEP or PEP requiring continued protection. ## Adult Dosing ### Standard Dosing **Pre-exposure Prophylaxis (PrEP)** - **Dose**: **1 mL** - **Frequency**: Days **0, 7, 21 or 28**. - **Route**: Intramuscular (IM) into the deltoid. - **Duration**: 3-dose series. **Post-exposure Prophylaxis (PEP) - Unvaccinated Individuals** - **Dose**: **1 mL** - **Frequency**: Days **0, 3, 7, 14, and 28**. - **Route**: Intramuscular (IM) into the deltoid. - **Duration**: 5-dose series. (Rabies Immune Globulin (RIG) also given at Day 0). **Post-exposure Prophylaxis (PEP) - Previously Vaccinated Individuals** - **Dose**: **1 mL** - **Frequency**: Days **0 and 3**. - **Route**: Intramuscular (IM) into the deltoid. - **Duration**: 2-dose series. (RIG is NOT given). ### Dose Adjustments - **Renal Impairment**: No specific dose adjustment required. - **Hepatic Impairment**: No specific dose adjustment required. - **Elderly Patients**: No specific dose adjustment required; administer as per adult dosing. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: **1 mL** for PEP or PrEP. - **Frequency**: As per adult schedules (e.g., Day 0, 3, 7, 14, 28 for PEP). - **Maximum**: Not applicable, standard dose for all ages. - **Special Notes**: Administer IM into the anterolateral aspect of the thigh. ### Infants (1-12 months) - **Dose**: **1 mL** for PEP or PrEP. - **Frequency**: As per adult schedules. - **Maximum**: Not applicable, standard dose for all ages. - **Special Notes**: Administer IM into the anterolateral aspect of the thigh. ### Children (1-12 years) - **Dose**: **1 mL** for PEP or PrEP. - **Frequency**: As per adult schedules. - **Maximum**: Adult dose equivalent. - **Special Notes**: Administer IM into the deltoid (if muscle mass sufficient) or anterolateral thigh. ### Adolescents (13-18 years) - **Dose**: **1 mL** for PEP or PrEP. - **Maximum**: Adult dose. - **Special Notes**: Administer IM into the deltoid. ## Safety Information ### Contraindications - **Absolute (for PrEP)**: Documented severe allergic reaction (anaphylaxis) to a prior dose or vaccine component. - **Absolute (for PrEP)**: Acute severe febrile illness; defer PrEP until recovery. - **Relative (for PrEP)**: Mild acute illness; may defer until recovery. - **Absolute (for PEP)**: No absolute contraindication; rabies is nearly 100% fatal, so PEP is always indicated. ### Common Adverse Effects - **Very Common (>10%)**: Injection site pain, swelling, redness, itching. - **Common (1-10%)**: Headache, nausea, abdominal pain, muscle aches, dizziness, malaise, fever. - **Serious but Rare**: Anaphylaxis, neurological reactions (e.g., Guillain-Barré syndrome, rarely reported). ### Key Drug Interactions - **Corticosteroids/Immunosuppressants**: May reduce antibody response; consider serologic testing for adequate response. - **Chloroquine/Mefloquine (for ID PrEP)**: May interfere with antibody response if given concurrently with intradermal PrEP; avoid or use IM vaccine. ## Monitoring & Follow-up - **Before Treatment**: Assess exposure type, animal status (if PEP), and vaccination history. - **During Treatment**: Monitor for immediate allergic reactions for 15-20 minutes post-injection. Monitor for local and systemic adverse effects. - **Clinical Signs**: For PEP, monitor for any signs of rabies progression (rare if PEP initiated promptly). ## Clinical Pearls - 💡 **Timeliness is Critical**: For PEP, initiate as soon as possible after exposure; delays can be fatal. - 💡 **RIG with PEP**: Rabies Immune Globulin (RIG) is crucial for **unvaccinated** PEP recipients at Day 0 for immediate passive immunity. Do NOT give RIG to previously vaccinated individuals. - 💡 **Injection Site**: Always administer IM into the deltoid for adults/older children and anterolateral thigh for infants/young children. Never in the gluteal region. - 💡 **Formulation Specifics**: Be aware of specific product instructions (e.g., reconstitution, IM vs. ID formulations). - 💡 **Pre-exposure Titers**: For ongoing high-risk individuals, periodic serologic testing may be recommended, with booster doses if levels fall below protective thresholds. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.