Rabies can only be contracted if the source of infection, the route of transmission, and the susceptible population are all met at the same time, and if the bite or scratch is not followed by formal immunization. To get rabies, first of all, the source of infection, the animal that bites or scratches itself must be an animal carrying the rabies virus or already suffering from rabies. The way it passes must be by scratching or biting, or by licking a person’s mucous membranes or unhealed wounds, so that the virus can enter the person’s body from the infectious animal. After entering a person’s body, the person must not have the relevant immunity to cause a rabies attack. If a person has been vaccinated against rabies some time before and has rabies virus neutralizing antibodies of 0.5 IU/mL or more in their body, they generally will not get rabies. The last thing is that a person may be infected with rabies only if he or she is not promptly injected with rabies vaccine or serum or immunoglobulin after being bitten or scratched.