The acyw vaccine is a vaccine that protects against meningococcus of group a, c, y, and w types. The acyw vaccine is one of the vaccines required by the state, and is mainly used for the prevention of epidemic cerebrospinal meningitis (ECM) in children. Epidemic cerebrospinal meningitis in children is a serious pediatric disease that not only threatens the health of children, but also places a heavy burden on society and families. It is generally recommended that preschool children be injected with this vaccine, which can effectively prevent meningitis caused by meningococcal infections of group A, group C, group Y, group W and other types of meningococcal infections. It is recommended to ensure that the child is in good health before vaccination. If the child is in an acute stage of infection, such as fever, the child should wait until the disease recovers before receiving the vaccine. If the child is not feeling well after vaccination, he should consult a doctor promptly.