This is Phase 4 clinical trial of live attenuated varicella vaccines manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd .The purpose of this study is to evaluate the immunogenicity and safety of a single dose of varicella vaccine in healthy children aged 1-6 years with different varicella immunization histories, to evaluate the antibody level of varicella-zoster virus in healthy people aged 0-59 years in Zhejiang Province.

This study is Phase Ⅳ clinical trial.The experimental vaccine manufactured by Sinovac(Dalian) Vaccine Technology Co., Ltd.This clinical trial consists of five parts,and A total of 37920 subjects will be enrolled.

Study 1,360 subjects including 120 subjects aged 1-3 years with no history of varicella vaccination ,240 subjects aged 4-6 years with a history of 1 dose of varicella vaccine will be enrolled to evaluate the immunogenicity and safety of varicella vaccine.All subjects will receive one dose of varicella vaccine.

Study 2,2530 subjects aged 0-59 years old will be enrolled and will be collected venous blood to detect varicella antibody and conduct investigation of varicella antibody level in healthy people.

Study 3,30000 subjects aged 1-12 years old will be enrolled to conduct safety observation study.All subjects will receive one dose of varicella vaccine and all adverse events of all subjects will be collected.

Study 4,5000 subjects aged 1-12 years old will be enrolled to conduct protective effect study of varicella vaccine after exposure.

Study 5,30 subjects aged 1-12 years old will be enrolled. Herpes fluid or pharyngeal swab samples of subjects will be collected to study the pathogenicity of varicella.

Unified Inclusion Criteria:

• Participants aged 1-12 years ;
• The subjects and/or guardians can understand and voluntarily sign the informed consent form (For subjects aged 8-12 years, both subjects and guardians need to sign the informed consent form) and be able to follow all research procedures;
• Proven legal identity.

Special Inclusion Criteria for each study:

Inclusion criteria of the study population for immunogenicity and safety evaluation of varicella vaccine:

• Be able to participate in the whole process of vaccination and blood collection;
• Healthy children aged 1-3 years with no history of varicella vaccination;
• Healthy children aged 4-6 years with a history of 1 dose of varicella vaccine.

Inclusion criteria for investigation of varicella antibody level:

• Healthy people aged 0-59 years and participate voluntarily for the study;
• Have no serious chronic disease or acute disease;

Inclusion criteria of the study population for safety evaluation of varicella vaccine mass vaccination:

• Participants aged 1-3 years with no history of varicella vaccination;
• Participants aged 4-12 years with no history of varicella vaccination or with a history of 1 dose of varicella vaccine.

Inclusion criteria of study population for protective effect of varicella vaccine after exposure:

• Children aged 1-12 years exposed to varicella outbreaks;
• History with no varicella or shingles;

Inclusion criteria of study population for etiological study on the pathogenic strains of varicella cases:

• Clinical cases of varicella consent for herpes zoster or pharyngeal swab collection.

Exclusion Criteria:

• History of 2 doses of varicella vaccination;
• Previous history of varicella or herpes zoster (not applicable to investigation of varicella antibody level);
• History of severe allergic reactions to vaccines (e.g.acute anaphylaxis, angioneurotic edema, dyspnea, etc.);
• Suffering from acute disease or acute episode of chronic disease;
• Any confirmed or suspected immunodeficiency disease, including human immunodeficiency virus (HIV) infection;
• Axillary temperature >37.0°C;
• Receipt of other investigational drugs in the past 30 days;
• Receipt of attenuated live vaccines in the past 28 days;
• Receipt of inactivated or subunit vaccines in the past 7 days;
• According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.