Risk of Rabies from Accidental Human Administration of Animal Rabies Vaccine
If a modified live animal rabies vaccine (MLV) is accidentally given to a person, there is no documented risk of rabies transmission, and postexposure treatment is not recommended. 1
Evidence for Safety
The Advisory Committee on Immunization Practices has specifically addressed this scenario and provides clear guidance:
No human rabies cases have ever been reported from accidental exposure to licensed modified live rabies virus (MLV) vaccines used in animals, despite frequent inadvertent exposures over decades. 1
The HEP (high egg passage) Flury strain—the attenuated rabies virus strain used in current animal vaccines—has been used for more than 25 years without any evidence of causing disease in humans who were accidentally exposed. 1
The best evidence for the low risk is the complete absence of recognized cases of vaccine-associated rabies among humans despite frequent inadvertent exposures through needle sticks and sprays during veterinary practice. 1
Clinical Management
No postexposure prophylaxis is indicated following accidental human exposure to HEP Flury strain animal vaccines. 1
Important Caveats
While vaccine-induced rabies has occurred in animals given these MLV vaccines, this phenomenon has never been documented in humans. 1
The guidelines acknowledge that "absolute assurance of a lack of risk for humans cannot be given," but the decades of safety data support non-intervention. 1
Because insufficient data exist to assess the true risk of any MLV vaccine exposure, the ACIP recommends that veterinary personnel who frequently handle these vaccines should receive preexposure rabies vaccination and periodic boosters—but this is a preventive measure for occupational exposure risk, not a response to accidental inoculation. 1
Key Distinction
This guidance applies specifically to licensed MLV vaccines containing attenuated virus strains (like HEP Flury). It does not apply to:
- Killed/inactivated animal vaccines (which pose no risk)
- Unlicensed or experimental vaccines
- Exposure to wild-type rabies virus
The person who received the animal vaccine by mistake does not need rabies postexposure prophylaxis, but should be monitored for any unusual symptoms and reassured about the excellent safety record of these vaccines in humans. 1