The purpose of this clinical study is to evaluate the safety and immunogenicity of receiving two doses of recombinant herpes zoster vaccine (CHO cells) (RHZV) in healthy individuals aged 40 years and above. This study will be conducted in 2 substudies: Substudy A (Phase I) and Substudy B (Phase Ⅱ).

There are two parts of the study.

Substudy A:

This substudy is the Phase I portion of the study. In this substudy, participants will receive 1 of 2 RHZV candidates (different dose levels) or the approved shingles vaccine (positive control) or adjuvant controls or normal saline intramuscularly. Participants will be divided into 2 age groups: 40-49 years old and ≥ 50 years old. Participants will receive vaccinations on days 0 and 60. Participants will complete a 12-month safety follow-up after two doses of vaccination, and they will take part in this study for about 14 months.

Substudy B:

This substudy is the Phase Ⅱ portion of the study. In this part of the study, participants will also receive 1 of 2 RHZV candidates (different dose levels) or the approved shingles vaccine (positive control) or normal saline intramuscularly. Participants will be divided into 3 age groups: 40-49 years old, 50-69 years old and ≥ 70 years old. Participants will receive vaccinations on days 0 and 60. Some group(s) will continue into persistence-of-immunity (overtime assessment of effect of vaccine) portion of the study. Those participants will be involved in this study for up to 2 years.

Inclusion Criteria:

• Age ≥ 40 years old on the day of enrollment, gender not limited.
• Can provide legal proof of identity.
• Be able to understand the experimental procedure and sign a written informed consent form, expressing agreement to participate in the experiment.
• Be able to participate in all planned follow-up visits and comply with all trial procedures.
• On the day of enrollment, the body temperature was less than 37.3 ℃ (axillary temperature).
• Chronic disease patients need to be in a stable period of chronic disease.
• Female and male participants of childbearing age agreed to adopt strict and effective contraceptive measures from the start of the trial to 6 months after full exemption.

Exclusion Criteria:

• Individuals with a history of herpes zoster in the past.
• Individuals with a history of vaccination against chickenpox or shingles.
• Individuals who have had close contact with patients with chickenpox or shingles in the past 2 years.
• Women of childbearing age who have a positive urine pregnancy test, are breastfeeding, pregnant, or plan to become pregnant within 6 months after the start of the test and the full exemption period.
• Individuals who are allergic to any component of the vaccine or have a history of other severe allergies.
• Use immunoglobulin and/or any blood products within 3 months prior to administering the trial vaccine, or plan to use them during the trial period.
• Have taken antipyretic, analgesic, or anti allergic drugs within 72 hours prior to receiving the experimental vaccine.
• Any experimental or unregistered product (drug, vaccine, biological product or device) other than the experimental vaccine has been used within one month prior to vaccination, or is planned to be used during the trial period.
• Administer non live vaccines within 7 days prior to administering the experimental vaccine or live vaccines within 14 days prior to administering the experimental vaccine.
• Suffering from a serious illness that prevents the completion of the entire experiment.
• Received immunosuppressive therapy or other immunomodulatory drugs, monoclonal antibodies, thymosin, interferon, etc. within 6 months prior to vaccination with the experimental vaccine, or planned to receive such treatment within 1 month after the first dose to full immunization, but local medication is allowed.
• Chemotherapy, radiotherapy, and organ and bone marrow transplantation related treatments for cancer or other diseases.
• Diseases or medical measures that lead to immune dysfunction
• Individuals currently suffering from serious infectious diseases such as active tuberculosis and active viral hepatitis.
• Moderate or severe acute illness/infection, or febrile illness within 72 hours prior to vaccination.
• Known to have a history of thrombocytopenia, any coagulation dysfunction, or being treated with anticoagulants.
• Suffering from serious cardiovascular disease, pulmonary edema, serious liver and kidney disease, and diabetes that cannot be controlled by drugs.
• Previous history of mental and neurological disorders or family history of mental illness.
• Currently suffering from various severe infectious, suppurative, and allergic skin diseases.
• Plan to move before the end of the trial or leave the local area for a long time during the scheduled trial visit.
• (Phase I ) Abnormal blood routine, blood biochemistry, coagulation, and urine routine indicators before vaccination (excluding those judged by doctors to have no clinical significance).
• Any situation that the researcher believes may affect the evaluation of the experiment.