Healthcare providers administer pre-exposure prophylaxis with the rabies vaccine for several reasons. First, although pre-exposure vaccination does not eliminate the need for additional medical attention after a rabies exposure, it simplifies therapy by eliminating the need for human rabies immune globulin (HRIG), and decreases the number of rabies vaccine doses needed. Second, it may enhance immunity in people whose post-exposure rabies treatment might be delayed. Finally, it may provide protection to people with unapparent exposures to rabies.
Pre-exposure treatment with the rabies vaccine consists of three doses of rabies vaccine given on days 0, 7, and 21 or 28.
Doctors use post-exposure prophylaxis (rabies treatment) with the rabies vaccine for people possibly exposed to a rabid animal (see Rabies Transmission). Post-exposure treatment for rabies should begin as soon as possible after an exposure. According to the CDC, no one in the United States has developed rabies when this post-exposure treatment regimen was followed.
Administration of rabies vaccine is a medical urgency, not a medical emergency. Physicians should evaluate each possible exposure to rabies and, as necessary, consult with local or state public health officials regarding the need for rabies prophylaxis.
In the United States, post-exposure rabies treatment consists of a regimen of one dose of rabies immune globulin and five doses of rabies vaccine given over a 28-day period. Rabies immune globulin and the first dose of rabies vaccine should be given as soon as possible after exposure. Additional doses of rabies vaccine should be given on days 3, 7, 14, and 28 after the first vaccination.
The rabies vaccine works by stimulating a person's immune system to produce antibodies that neutralize the virus. The person develops a protective immune response before the virus reaches the brain and begins to actively replicate.