Rabies Vaccine Dosing Regimens
The standard rabies vaccination regimen consists of 4 doses for post-exposure prophylaxis in previously unvaccinated individuals, 3 doses for pre-exposure prophylaxis, and 2 doses for post-exposure prophylaxis in previously vaccinated individuals.
Post-Exposure Prophylaxis (PEP)
For Previously Unvaccinated Individuals:
- 4-dose regimen: 1.0 mL of Human Diploid Cell Vaccine (HDCV) or Purified Chick Embryo Cell Vaccine (PCECV) administered intramuscularly on days 0,3,7, and 14 1
- This is a reduction from the previously recommended 5-dose regimen, based on evidence showing that 4 vaccine doses combined with rabies immune globulin (RIG) elicit adequate immune responses
- Must be administered with rabies immune globulin (RIG) at a dose of 20 IU/kg body weight 2
- RIG should be infiltrated around the wound if anatomically feasible, with any remaining volume administered intramuscularly at a site distant from vaccine administration
For Previously Vaccinated Individuals:
- 2-dose regimen: 1.0 mL of HDCV or PCECV administered intramuscularly on days 0 and 3 1
- No RIG is required for previously vaccinated individuals
For Immunocompromised Individuals:
- 5-dose regimen: The standard remains 5 doses for persons with altered immunocompetence 1, 3
- Administered with 1 dose of RIG
Pre-Exposure Prophylaxis
- 3-dose regimen: 1.0 mL of HDCV or PCECV administered intramuscularly on days 0,7, and 21 or 28 1, 3
- This regimen is recommended for individuals at high risk of exposure to rabies virus (laboratory workers, veterinarians, animal control officers, wildlife officers in endemic areas, bat handlers, and travelers to endemic areas)
Administration Considerations
- Injection site should be the deltoid area for adults and older children, and the anterolateral thigh for young children 3
- The gluteal region should never be used as an injection site due to risk of sciatic nerve injury 2
- PEP should be initiated as soon as possible after exposure, ideally within 24 hours, but there is no absolute time limit for starting treatment 3
Booster Requirements
- For individuals with continuous risk (laboratory workers): Serum testing every 6 months and booster doses when titer falls below acceptable levels 3
- For individuals with frequent risk (veterinarians, animal control officers): Serum testing every 2 years or booster without titer testing 3
- For individuals with infrequent risk: No routine boosters required after completing primary vaccination 3
Important Considerations
- Proper wound cleansing is a critical first step in all rabies exposures, regardless of vaccination status
- Correctly administered post-exposure prophylaxis is nearly 100% effective in preventing rabies, which is almost invariably fatal once clinical symptoms appear 3
- Common errors that reduce effectiveness include failure to properly infiltrate wounds with RIG, improper injection site, delayed initiation, incomplete vaccination, and inadequate wound cleansing 3
The reduction from 5 to 4 doses for PEP in immunocompetent individuals represents an evidence-based change that maintains efficacy while reducing the burden of vaccination. This recommendation is supported by rabies virus pathogenesis data, experimental animal work, clinical studies, and epidemiologic surveillance 1.