Is Post-Exposure Prophylaxis (PEP) for rabies the same as the rabies vaccine?

Rabies Post-Exposure Prophylaxis vs. Rabies Vaccine

No, post-exposure prophylaxis (PEP) for rabies and rabies vaccine are not the same. PEP consists of wound care, rabies immune globulin (RIG), AND rabies vaccine, while the rabies vaccine alone is just one component of PEP for unvaccinated individuals.

Components of Rabies Post-Exposure Prophylaxis (PEP)

For previously unvaccinated persons, complete PEP consists of:

1. Wound care: Thorough washing and flushing of all wounds for about 15 minutes with soap and water, plus application of an iodine-containing or similar virucidal preparation when available 1, 2

2. Rabies Immune Globulin (RIG):

   • Administered once at 20 IU/kg body weight
   • Infiltrated in and around the wound(s) with any remaining volume injected intramuscularly at a site distant from vaccine administration
   • Must be given at the time of the first vaccine dose (day 0) or up to day 7 if not given initially 3, 4

3. Rabies Vaccine:

   • For healthy individuals: 4-dose regimen (1.0 mL each in the deltoid) on days 0,3,7, and 14 3, 4
   • For immunocompromised individuals: 5-dose regimen on days 0,3,7,14, and 28 3, 4

Different PEP Requirements Based on Prior Vaccination Status

For Previously Unvaccinated Persons:

• Complete PEP includes all three components: wound care, RIG, and the 4-dose vaccine series 3
• Both RIG and vaccine are recommended regardless of the interval between exposure and initiation of PEP 1

For Previously Vaccinated Persons:

• Only requires wound care and a shortened vaccine series (2 doses on days 0 and 3)
• RIG is NOT administered as it may interfere with the anamnestic immune response 3, 4

Important Considerations

• PEP should begin as soon as possible after exposure, but can be beneficial even months later if the person has not developed rabies symptoms 4
• If PEP has been initiated and laboratory testing confirms the animal was not rabid, PEP can be discontinued 3, 1
• The rabies vaccine alone (without RIG) is used for pre-exposure prophylaxis in high-risk individuals and for previously vaccinated individuals requiring PEP 1, 5
• Immunosuppressed patients require special consideration with the 5-dose regimen and should have antibody titers checked after vaccination 3, 4

Common Pitfalls to Avoid

1. Failing to administer RIG: Many patients only receive the vaccine component of PEP, which is insufficient for unvaccinated individuals exposed to rabies
2. Improper RIG administration: RIG should be infiltrated in and around all wounds first, with any remaining volume injected intramuscularly
3. Confusing pre-exposure prophylaxis with PEP: Pre-exposure prophylaxis uses only the vaccine (3 doses), while PEP for unvaccinated persons requires both RIG and vaccine
4. Delaying treatment: Rabies is nearly 100% fatal once symptoms develop, so PEP should never be delayed while waiting for animal testing results if the exposure risk is significant

Remember that rabies PEP is highly effective when administered correctly, but once clinical symptoms of rabies appear, the disease is almost invariably fatal. This underscores the critical importance of proper and timely administration of complete PEP.