Vaccines are useful. Vaccines are a primary means of preventing or reducing viral infections, and although they are not 100% protective against viruses, they are highly protective. Vaccines are administered so that the vaccinated party gains immunity against a specific or vaccine-like pathogen. Examples include the new coronavirus vaccine, the rabies virus vaccine, and the hepatitis B virus vaccine. Most vaccines are mainly specially treated viruses that, when injected into the body, allow the patient’s own immune system to produce the appropriate antibodies, thus preventing infection. Taking the XKV vaccine as an example, patients who have received the XKV vaccine will have a relatively lower chance of infection, a lower severity of illness, and a faster recovery time than patients who have not received the XKV vaccine. The current outbreak of New Crown Pneumonia is not fully under control, and those who have not received the New Crown vaccine or have not received the full course of the vaccine should be up to date with the New Crown vaccine. Although the vaccine is not 100% preventive, it is still relatively good protection. Even after vaccination, patients should pay attention to protective measures to prevent viral infection. Note: The terms “new coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.