Rabies post-exposure prophylaxis is different because it's made up of several components: human rabies immune globulin (HRIG) and the vaccine. The vaccine takes

Rabies post-exposure prophylaxis is different because it's made up of several components: human rabies immune globulin (HRIG) and the vaccine. The vaccine takes a while to work so HRIG is the first line of defense that prevents the virus from entering the nervous system until the immune system is able to fight the virus.