Rabies is a viral disease transmitted by animals that cause acute inflamation of the brain (encephalitis). The vaccine is 
given at high risk of rabies to protect them if they are exposed. The following are information you might need regarding rabies vaccine in frequently asked questions which was issued by the CDC.
You will be explained with information from questions such as what is rabies, what rabies vaccine made from, who should get rabies vaccine and when (preventive vaccination, vaccination after an exposure), what are the risks from rabies vaccine, and what if there is a moderate or severe reaction.
Complete read about Rabies Vaccine in FAQ can be download here in this rabies article of pdf filetype (source: cdc.gov)
