The mechanism of rabies vaccine is to stimulate the immune system to produce antibodies against rabies virus. What really works is the antibody, not the vaccine itself. Generally, there will be some allergic reactions after injection, but most of them are very mild, and then they will return to normal, and it is impossible to leave any sequelae.
In addition, the first three injections are the most important for rabies vaccine, because the first three injections play the most important role in the formation of antibodies, and the last two injections are actually mainly to enhance the effect. Generally, three injections can be considered safe, but it is still recommended to finish the last two injections as required.