The A+C conjugate meningitis vaccine needs to be administered once when the child reaches the age of 3 and once when the child reaches the age of 6, with an interval of not less than three years between the two vaccinations. Currently, the meningitis vaccine is mainly used to prevent purulent meningitis caused by meningococcal infection. This kind of meningitis is often an acute infectious disease that appears in winter and spring, and is mainly transmitted through the respiratory tract, and the affected children will have fever, severe headache, vomiting, drowsiness, or even coma, as well as convulsive seizures and cor pulmonale. Some patients will also see large bruises and spots under the mucous membrane of the skin, and in severe cases, localized skin necrosis will occur. The best way to prevent severe epidemic is to vaccinate against epidemic encephalitis. Usually, after vaccination against epidemic encephalitis, the clinical adverse reactions are usually mild, some people may have redness and pressure pain at the injection site, but most of them can subside within 24 hours. Some patients may have redness and tenderness at the injection site, but most of them can subside within 24 hours. A few patients may have transient fever, but usually no special treatment is needed.