Depending on individual factors, the subsequent reaction to the New Crown vaccine may be characterized by no abnormal reaction, or it may result in an adverse post-vaccination reaction. Adverse reactions can be categorized into local reactions and systemic reactions. 1. Local reactions: some vaccinees may experience local pain, redness, swelling, itching and other symptoms, which usually resolve on their own in 2~3 days. 2. Systemic reaction: mainly low fever, may also appear fatigue, headache, myalgia, nausea, diarrhea, cough, runny nose, hypersensitivity reaction, etc., usually will be relieved by themselves. Serious cases should seek medical treatment in time. It is recommended to stay for 30 minutes after vaccination. If minor adverse reactions are found at home, they can be relieved on their own without treatment, or if the discomfort is more pronounced, they can be treated symptomatically under the guidance of a doctor.