Lyophilized herpes zoster mRNA vaccine given to adults 40 and older

Inclusion Criteria:

1. Be able and willing to comply with the protocol requirements for all scheduled follow up visits, agree to participate in the trial, and voluntarily sign the ICF approved by EC;
2. Chinese male or female aged ≥40 year. Participants with underlying medical conditions may be enrolled if their conditions are stably controlled;
3. Be able to communicate well with the investigator, understand and comply with the protocol requirements for trial participation;
4. Female participants of childbearing potential and male participants (whose female partners are of childbearing potential) must have practiced effective contraception from the end of the last menstrual cycle of the female participant or partner until the day of vaccination, and must continue to use effective contraception for 6 months after completion of the voluntary vaccination. During this period, they must also refrain from donating sperm or ova. Alternatively, female participants may be considered not of childbearing potential.

Exclusion Criteria:

1. Within 3 days prior to vaccination, presence of acute illness, acute exacerbation of chronic disease, or febrile/near febrile state, or use of anti inflammatory drugs, antibiotics, antihistamines, or antiviral drugs due to physical discomfort;
2. On the day of vaccination, for participants aged 40-59 years, systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg; for participants aged ≥60 years, systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg;
3. Female participants who are known to be pregnant or breastfeeding, or who have a positive pregnancy test if of childbearing potential;
4. History of allergy to any component of the investigational vaccine, or history of severe allergic reactions to other vaccines, foods, or drugs;
5. History of herpes zoster (shingles), history of varicella (chickenpox) within the past year, or close contact with individuals with varicella/herpes zoster within the past year;
6. Previous or planned vaccination with herpes zoster or varicella vaccines (including licensed or unlicensed vaccines) during the trial period;
7. Use of any vaccine within 30 days prior to vaccination, or planned use of any vaccine other than the investigational vaccine within 30 days after administration of the investigational vaccine;
8. Current participation in another drug or medical device clinical trial within 6 months prior to vaccination, or planned participation in such a trial before the end of this trial;
9. History of clinically diagnosed coagulation abnormalities or coagulation disorders, or contraindications to intramuscular injection such as receiving anticoagulant therapy;
10. Known medical history or diagnosis confirming that the participant has or has had a disease affecting immune system function, including malignancies, congenital or acquired immunodeficiencies, autoimmune diseases, or other conditions affecting immune function;
11. History of myocarditis, pericarditis, or idiopathic cardiomyopathy, or any condition that increases the risk of myocarditis or pericarditis;
12. Uncontrolled cardiovascular diseases, severe or uncontrolled respiratory diseases, neurological diseases, hematological and lymphatic diseases, liver and kidney diseases, metabolic and skeletal system diseases, or known severe congenital malformations, developmental disorders, or clinically diagnosed severe chronic diseases that, in the investigator's judgment, may affect the trial results;
13. Acute infection, acute phase of chronic infection, or currently receiving anti tuberculosis treatment, or those with a previous positive treponemal antibody test;
14. History or current presence of clearly diagnosed neurological diseases or psychiatric disorders or family history of neurological/psychiatric diseases, receipt of facial fillers within 6 months prior to vaccination, and other neurological diseases that the investigator deems unsuitable for participation;
15. Current skin diseases that, in the investigator's judgment, may affect trial observations;
16. Use of long term immunosuppressive therapy or other immunomodulatory drugs within 6 months prior to vaccination, or planned use during the period from enrollment to 1 month after the full course of vaccination, with the exception of topical drugs. Topical drugs should not exceed the recommended dose in the package insert or induce signs of systemic exposure. Long term systemic corticosteroids for ≥14 days at a dose of ≥2 mg/kg/day or ≥20 mg/day prednisone or equivalent;
17. Receipt of immunoglobulins and/or blood products, or blood donation, within 3 months prior to vaccination, or planned during the period from enrollment to 1 month after the full course of vaccination;
18. Suspected or known drug abuse that, in the investigator's opinion, may affect safety evaluation or trial compliance;
19. Investigators at the trial site/study site, or employees of the sponsor or third party monitoring company involved in the trial;
20. Other conditions that the investigator deems unsuitable for participation in this trial.