I. Measles is a category B infectious disease caused by the measles virus acute systemic rash respiratory infections, highly contagious, who have not suffered from measles and have not been vaccinated against measles are susceptible, more than 90% of the disease after contact. The incubation period is about 10 days, up to 21 days. The main clinical manifestations are fever, runny nose, conjunctivitis, cough and skin maculopapular rash. The vaccine is a class I vaccine. The disease is an acute respiratory infection caused by Meningococcus meningitidis infection. Incubation period of 1-7 days, the initial onset of influenza resembles a cold, runny nose, cough, headache fever, etc.. After the germs enter the cerebrospinal fluid, headache increases, drowsiness, neck tonicity, jet-like vomiting and coma shock and other critical symptoms. There are two clinical types: common and fulminant, and the fulminant type has a very high mortality rate. Rubella is a category C infectious disease. It is a common viral infection in childhood with an incubation period of 14-21 days, characterized by mild systemic symptoms, red skin papules and swollen lymph nodes behind the occiput, behind the ear and behind the neck with tenderness. Mumps is a category C infectious disease, also known as “ear infection”, which occurs on one or both sides of the cheek and is characterized by swelling, fever, non-pus, and easy transmission. It is common in winter and spring. The incidence is higher in children between 4 and 15 years old, and the symptoms are often more severe in adults than in children. The disease can develop throughout the year, but is more common in winter and spring. It is extremely rare for a person to be re-infected with the disease after a single episode of the disease and to have lasting immunity. The disease can be complicated by orchitis, heavy encephalitis and cardiomyopathy. V. Chickenpox is a common respiratory infection that occurs in young children, but adults can also be infected with the disease. The main symptoms are fever, rash, papules, herpes, itching or pain. It is a self-limiting disease that can heal itself within 10 days without sequelae. The main symptoms of pediatric pneumonia are fever, cough, shortness of breath and dry incitement. The cause is mainly due to the feeling of wind-cold, or wind-heat outside the evil; in addition, in the process of some other rash disease, if the child is weak, can also complicate or secondary to this disease.