Group A+C Meningococcal Conjugate Vaccine (MCCV) is a group A+C meningococcal polysaccharide conjugate vaccine, which requires two doses for infants and toddlers between 6 months and 2 years of age, and one dose for children over 2 years of age. Meningococcal Polysaccharide Conjugate Vaccine (MCCV) is a biological agent with the ability to prevent epidemic cerebrospinal meningitis caused by meningococcal groups A and C. The results of clinical trials show that infants and children under 2 years of age have a better immune response to the vaccine, so infants and children under 2 years of age are the main applicability of this vaccine, and the primary immunization is two injections, with an interval of one month between each injection. Children over 2 years of age can be immunized with either group A group C meningococcal polysaccharide vaccine or group A group C meningococcal polysaccharide conjugate vaccine, and only one dose is needed if the vaccine is a group A group C meningococcal polysaccharide vaccine. Vaccination with Group A Group C Meningococcal Polysaccharide Conjugate Vaccine may cause adverse reactions such as headache, fever, rash, loss of appetite, and malaise, which are usually transient and resolve on their own. After receiving Meningococcal Polysaccharide Conjugate Vaccine Group A and C, it is necessary to remain in the hospital for thirty minutes without any discomfort before leaving, and consult your physician if you feel unwell.