Rabies vaccine can be given twice a year, because if you are bitten or scratched by cats or dogs accidentally and have to take rabies vaccine, you will be able to achieve normal immunity after taking five injections within a month, but the antibodies in your body will exist in your body for about a month, and if you are bitten or scratched by cats or dogs again after a month, you still have to take the second course of the vaccine. Rabies vaccine does not have much adverse reaction to the body, if the human body is not allergic to the vaccine, such as redness, swelling, itching or numbness at the injection site, rashes all over the body and other allergic reactions, twice a year is not a problem, and will not cause any damage to the body.