A Study on the Live-Attenuated Herpes Zoster Vaccine for Sequential Booster Immunization Following Recombinant Herpes Zoster Vaccine

Inclusion Criteria: * Age ≥ 50 years old; * The participant can provide personal informed consent and sign the informed consent form; * temperature ≤ 37.0℃ on the day of administration; * capable of complying with the requirements of the clinical trial protocol to complete the trial. Exclusion Criteria: * Subjects with immunodeficiency or immunosuppression caused by underlying diseases or treatments, including primary/acquired immunodeficiency (e.g., AIDS and other virus-induced immunodeficiency), hematologic malignancies (leukemia, lymphoma or other bone marrow/lymphoid neoplasms), ongoing immunosuppressive therapy, or radiotherapy/chemotherapy for malignancies. * Subjects with a history of allergic reaction to any component of the investigational product. * Subjects with acute infection or acute exacerbation of chronic infection (vaccination should be deferred). * Women of non-postmenopausal status with positive pregnancy test, pregnant or lactating women, or those planning pregnancy within 6 months. * Subjects with prior history of herpes zoster. * Subjects with prior receipt of varicella or herpes zoster vaccine. * Receipt of live-attenuated vaccines within 14 days, or subunit/inactivated vaccines within 7 days prior to study vaccination. * Receipt of whole-blood, plasma or immunoglobulin within 5 months before, or within 3 weeks after study vaccination. * Receipt of investigational drugs from other clinical trials within 1 month before study vaccination, current participation in another clinical trial, or planned use of investigational agents during study period. * Current or planned use of salicylates (including aspirin, diflunisal, etc.). * Uncontrolled abnormal blood pressure at screening (systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg despite medication). Subjects meeting contraindications or precautions specified in the product's prescribing information. * Any condition that, in the Investigator's opinion, may interfere with study evaluations.