Currently, two or three doses of vaccines are required, mainly including the New Crown vaccine and the cervical cancer vaccine. For example, the two-dose New Crown vaccine is an inactivated vaccine, while the three-dose New Crown vaccine is a recombinant protein vaccine. Both vaccines meet the national or international standards for vaccine development, and patients can choose the two-dose vaccine or the three-dose vaccine according to their own situation, vaccination characteristics of the vaccine, etc. The difference between the two vaccines is mainly in the following aspects: 1. vaccine composition: the composition of the two-dose vaccine is similar to the structure of the virus, which can produce a broad-spectrum immune response; while the main component of the three-dose vaccine is the recombinant product of the virus receptor, which contains less virus, so three doses are needed to achieve the effect; 2. production process: the production process of the two-dose vaccine is more mature, with more stable quality and fewer side effects, and is convenient for transportation and storage; while the three-dose vaccine is produced in accordance with national or international standards for vaccine development. 3. Vaccination interval: Generally, two-dose vaccines require an interval of 3-8 weeks. The first two doses need to be given at an interval of 4-8 weeks, while the third dose needs to be completed within 6 months after the first dose. Both the two-dose vaccine and the three-dose vaccine can be used to prevent the disease, but no vaccine is clinically available to provide 100% prevention. Patients also need to protect themselves after vaccination to reduce the development of infectious diseases.