New crown vaccination may cause fever, local redness and swelling, loss of appetite, fatigue, allergic reactions and other adverse reactions. Injection of new crown vaccine may cause certain adverse reactions, more common in the local skin after vaccination may appear itching, redness, swelling, pain, hard nodules, etc., can subside after rest and hot compresses. Some vaccinated people may have fever, most of them are low fever, which can subside soon, and some people may have high fever. Symptoms such as loss of appetite and feeling weak may also occur. Allergic patients may have an allergic reaction to the New Crown vaccine, which may be manifested as a skin rash, and in severe cases may cause symptoms such as chest tightness and difficulty in breathing. Overall, the safety of the new crown vaccine currently administered in China is relatively high, with no obvious serious adverse effects. Most of the adverse reactions are mild and can be gradually relieved, and those without contraindications should be actively vaccinated. After the new crown vaccine should be observed in the observation room for 30 minutes, if there is no abnormality before leaving, if there is an abnormality, promptly inform the doctor to deal with. Pay attention to the injection site, do not scratch with your hands to avoid infection. If any of the above adverse reactions occur, and if the symptoms are more serious, you need to seek medical attention promptly.