Adverse reactions to A+C influenza vaccine are relatively mild, and there are generally no serious local or systemic reactions after vaccination. Individual children may experience localized redness and mild pain for 1-2 days after vaccination, systemic reactions sometimes include low-grade fever, 1%-4% of vaccinees may experience fever over 38.5°C, and occasional allergic reactions. most vaccinees experience adverse reactions 10-24 hours after vaccination and generally recover on their own in 2-3 days, and symptomatic treatment can be given if necessary. the influenza A+C vaccine is divided into The free vaccine is mainly the Group A+C polysaccharide meningococcal vaccine, which is used to prevent epidemic meningitis caused by meningococcal groups A and C. The vaccination is given at the age of three weeks and six weeks, and the Group A+C conjugate vaccine is also used to prevent meningococcal meningitis caused by meningococcal groups A and C. It is mainly used for children and adults above the age of six months, with two doses of basic immunization, each dose being given at an interval of not less than one month. The interval between doses is not less than one month.