Inactivation is a means of vaccine production in which the activity of the virus is killed by physical or chemical means, while retaining its immune activity. The main purpose is to stimulate the body’s immune system to produce specific antibodies against the virus through the immune activity of the vaccine. Since there is no virus activity, it is safer and simpler to produce, but requires a larger dose of virus. Advantages and disadvantages are mainly reflected in: 1. Advantages: 1. simple production: Inactivated virus is made by physical or chemical means to kill pathogens, and the process is more mature; 2. easy to preserve and transport: Inactivated virus is more stable in nature, so it is relatively easier to transport and preserve; 3. easy to co-produce: Inactivated virus only retains immune activity and is stable in nature, so it is easier to make a combination vaccine or multivalent vaccine; 4. 4, high safety: because the virus activity has been killed, so it is safer and less likely to cause contamination. 2. Disadvantages: 1. the possibility of antigen damage: during the production process, there may be damage to the virus antigen, reducing the immune activity of the vaccine; 2. short maintenance time: the maintenance of immunity is relatively short, and the immunity can gradually drop over time, so multiple injections are needed, or booster injections at intervals, in order to achieve the expected immunization effect; 3. long vaccination time: usually inactivated virus requires 2-3 injections as one immunization program, and the dose of vaccination is usually large. Before inactivated vaccination, it is necessary to understand the scope of application and contraindications of the inactivated vaccine, etc., and communicate with the relevant medical personnel if you are not sure about the content. Try to wear loose clothing during vaccination to facilitate injection. If there are minor adverse reactions, such as low fever, dizziness, drowsiness, and slight pain at the vaccination site, there is usually no need to be anxious or worried, and they can be relieved in 2-3 days. If the adverse reaction is more serious, or if the patient is unsure, please seek prompt medical attention and professional help.