Immunization after a rabid animal bite is effective because it enhances the immune response, allowing the body to develop antibodies before the virus reaches the central nervous system. Human rabies immune globulin also provides passive immunity by neutralizing any viral particles. Humans aren't routinely vaccinated because of the low risk of exposure due to animal vaccination.
Effectiveness of Immunization Post-Rabies Exposure
Immunization after being bitten by a rabid animal is highly effective because the rabies vaccine enhances the immune response against the virus. The goal is to prevent the virus from reaching the central nervous system, which could be fatal. In the case of a rabies infection, the virus progresses slowly enough from the bite site to provide a window of opportunity for the vaccine to stimulate the patient's immune system to produce antibodies. Patients may also receive human rabies immune globulin, which provides passive immunity by neutralizing any present free viral particles in the patient's system.
People are not routinely vaccinated for rabies like domestic animals because it is uncommon for humans to contract rabies, largely due to the effective vaccination of animals themselves. The risk of exposure in humans is relatively low, and therefore, mass vaccination of the human population is not considered necessary or cost-effective.