To investigate the safety, immunogenicity and immune effect of the Varicella vaccine after the 2nd dose vaccination in Chao yang district, Bei jing, since the 2nd varicella vaccination was promoted by Beijing Center for Disease Control and Prevention in November, 2012.

"Breakthrough" varicella cases and varicella cases were monitored to evaluate the protective effective in a large population.

Make the basic evaluation of safety for the two dose of varicella vaccination

Monitoring the Varicella virus origin and virus types from illness cases in Chao yang district

Make the evaluation of healthy costs reduce for the varicella emergency vaccination after large number of varicella cases occurred.

Inclusion Criteria:

• Participants were between 4-12 years old
• Participants were in good healthy determined through medical history, physical examination, clinical judgment of the investor

Exclusion Criteria:

• Having a fever (axillary temperature >37.0℃) before enrollment;
• Having a disease history of seizures, brain and mental disease and the vaccination history of allergies and convulsions;
• Antibiotics allergy;
• Having a problem of intramuscular injection because thrombocytopenia or other blood coagulation disorder;
• Having immunodeficiency or under immunosuppression therapy, radiation therapy;
• Having respiratory diseases, acute infection, chronic disease and HIV infection;
• Having systemic skin rash, skin tinea, herpes;
• Chronic liver and kidney disease;
• Heart disease, and severe hypertension;
• Have received whole blood, plasma or immunoglobulin therapy 3 months before enrollment;
• Have not received other vaccination in 7 days before enrollment