Fever may occur within 1 day after vaccination, usually no more than 3 days and often less than 38.5°C. Fever caused by vaccination is a common adverse reaction after vaccination and has nothing to do with the success of vaccination or the production of antibodies in the body, so there is no such thing as good or bad. The main mechanism of action of a vaccine is to inject inactivated pathogenic microorganisms, or pathogenic microorganisms with reduced virulence, into the body to produce a reaction with the immune system, causing the body to produce antibodies and thus gain immunity against the disease. After the immune system reacts, systemic symptoms such as fever, loss of appetite, sleepiness, and fatigue may occur, which are basically normal. If you have a fever after vaccination, you do not need special treatment. If the fever is higher than 38.5℃ or does not subside for a long time, it is recommended to consult a doctor and apply antipyretic drugs, such as ibuprofen and acetaminophen, under the guidance of a doctor. In addition, physical cooling, such as warm water swabbing baths, can be applied to relieve the fever. Avoid getting water on the injection site for 24 hours after vaccination and avoid bathing as much as possible. Prevent straining after vaccination and eat lean meat, soy milk and other foods appropriately to supplement protein.