If left untreated, rabies runs its course very rapidly. Once symptoms begin to appear, the disease is almost always fatal. The acute period of disease typically ends after 2 to 10 days. Common complications of rabies include, psychosis, seizures, aphasia, muscular twitching, delirium and death. Treatment after exposure (receiving the vaccines), known as post-exposure prophylaxis (PEP), is highly successful in preventing the disease if administered promptly, in general within ten days of infection.

• Rabies runs its course very rapidly throughout the body. Once symptoms begin to appear, the disease is almost always fatal.^[1][2]
• The period between infection and the first flu-like symptoms is normally two to twelve weeks, but can be as long as two years.^[3][4][5][6]
• The acute period of disease typically ends after 2 to 10 days.
• To date only six documented cases of human survival from clinical rabies have been reported and each included a history of either pre- or postexposure prophylaxis.
• The few humans who are known to have survived the disease were all left with severe brain damage, with the recent exception of Jeanna Giese.

Common complications of rabies include:^[7][8][9]

• Psychosis
• Seizures
• Aphasia
• Muscular twitching
• Restlessness
• Delirium
• Death

Treatment after exposure (receiving the vaccines), known as post-exposure prophylaxis (PEP), is highly successful in preventing the disease if administered promptly, in general within ten days of infection. Begun with little or no delay, PEP is 100% effective against rabies.^[10] In the case in which there has been a significant delay in administering PEP, the treatment should be administered regardless of that delay, as it may still be effective.

In unvaccinated humans, rabies is usually fatal after neurological symptoms have developed, but prompt post-exposure vaccination may prevent the virus from progressing. Rabies kills around 55,000 people a year, mostly in Asia and Africa.^[11]

Survival data using the Milwaukee protocol are available from the rabies registry.^[12] As of 2011, seven people have been saved by this induced coma treatment.