Fever is a relatively common adverse reaction after vaccination because the ingredients in the vaccine may sometimes cause a transient fever, but it usually does not exceed 38.5°C and lasts for a short time. In case of this kind of fever, you can monitor the change of body temperature regularly, as long as the fluctuation of body temperature is not big and there are no adverse reactions such as allergy, chills and headache, drink more water, keep warm, avoid straining, eat lightly, take vitamin supplements, do not smoke and drink, and do not eat spicy, stimulating and greasy food. Generally, fever symptoms will gradually disappear within 2-3 days. If the fever is high, you can also take appropriate antipyretic drugs or relieve the symptoms by physical cooling. However, if the temperature exceeds 38.5℃ and is accompanied by other serious adverse reactions, an abnormal reaction should be highly suspected and it is recommended to actively seek medical attention and treatment under the guidance of a doctor to avoid delay and to determine whether it is an abnormal reaction. If an abnormal reaction is suspected, promptly report the vaccination site, or the county-level disease control agency where the vaccination unit is located, and provide information about the vaccinator’s relevant medical records, medical history, and medication as soon as possible. If the fever is only caused by inflammation, fever-reducing drugs can be used under the guidance of a doctor to control the body temperature and avoid high fever convulsions. In addition to low fever, common adverse reactions to the new crown vaccine include local redness, hard nodules, weakness, nausea, headache, etc. However, these are all transient reactions of the body, caused by the biological characteristics of the vaccine itself, and the symptoms will gradually disappear 2-3 days, or within a week, after vaccination, so there is no need to worry.