The rabies vaccine is used to prevent rabies attacks. The principle of rabies vaccine to prevent rabies attacks is that the vaccine allows the body to produce the appropriate neutralizing antibodies, which are at an effective level and last for a relatively long period of time, thus preventing rabies. This antibody level must be at least 0.5 IU/ml. The rabies vaccination is administered by five injections to bring the rabies neutralizing antibodies to this level and maintain it for a longer period of time to prevent rabies. If one of the five injections of the rabies vaccine is missed or the last one is missed, it is possible that the rabies antibodies may reach above 0.5 IU/ml, but they will not last too long and may cause the prevention to fail.