Infants can usually add complementary food 3-7 days after vaccination, but need to be careful not to add allergy-prone complementary food such as egg yolk. After vaccination, the body of infants may experience some adverse reactions after vaccination, including local adverse reactions and systemic adverse reactions. Localized adverse reactions are mainly redness, swelling and pain at the vaccination site. Systemic adverse reactions are mainly mild fever, headache and dizziness, nausea, gastrointestinal disorders and so on. These adverse reactions usually subside within 3 to 7 days after vaccination, at which time complementary foods can be added. When adding complementary foods to infants, care should be taken not to add allergy-prone foods such as minced meat and mashed eggs, which are not easily digested at the same time and may cause diarrhea and other symptoms in infants.