Depending on the type of New Crown vaccine, the clinical vaccination doses are divided into one, two and three doses. The first possibility is that some patients do not have effective antibodies in their bodies or their antibody levels are not sufficient, so they may need to increase the number of vaccinations under the guidance of a professional doctor; in this case, choosing multiple vaccinations may have more advantages than disadvantages, but it is relatively rare. In the second case, the number of vaccinations may be increased because the patient forgets the number of vaccinations, and there may be certain adverse reactions in this case. However, since personal information is required for registration of the vaccination, this is also rare. Since the New Crown vaccine has been developed for a short period of time, there are no clear studies on the dangers of repeating four doses. However, in theory, repeating four doses of the New Crown vaccine may have some effect on the body’s immune system, which in turn increases the risk of causing uncomfortable reactions, such as dizziness, fatigue, weakness, fever and other symptoms in some people, or aggravation of vaccination reactions. It is important to note that the effectiveness of the new crown vaccine is not determined by the number of vaccinations given, and the more times the vaccination is given, the better the body’s ability to fight the virus in question. On the contrary, it may cause the problem of reduced effectiveness of the vaccine. Usually, the number of doses of vaccination has been developed through in-depth research by professional researchers, and it is recommended to follow the normal vaccination process, except in very special cases, such as when the body does not produce effective antibodies, where the number of doses can be increased on the advice of the doctor. Patients who have already received four doses of New Crown vaccine are advised to pay close attention to their health condition and to go to the hospital for examination if they experience any uncomfortable symptoms in order to avoid serious adverse reactions.