Immunogenicity, Safety and Protective Effect of Live Attenuated Varicella Vaccine and Study on Antibody Level and Etiology of Varicella Zoster Virus

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.