Inclusion Criteria:  Healthy subjects aged 18 and above with full capacity for civil conduct, who can provide valid identification; The subjects voluntarily agree to participate in the study and sign the informed consent to understand and comply with the requirements of the study protocol; Fertile men and women of reproductive age did not have sex from day 1 of the last menstrual cycle to day 1 of the study, or did not have sex using effective contraceptive methods and did not experience contraceptive failure (examples of contraceptive failure include male condom rupture during sex). At the same time, subjects agreed to take effective contraceptive measures for 1 month from the signing of informed consent to the full immunization and no pregnancy plans during this period.  Exclusion Criteria:  History of novel coronavirus infection confirmed or asymptomatic infected persons or positive nucleic acid test of novel Coronavirus; SARS virus history; For those with fever, axillary temperature ≥37.3℃ on the day of inclusion; A past history of severe allergy to any vaccine, or to the active ingredient of the test vaccine, any inactive ingredient, or substance used in the manufacturing process, including aluminum preparations, egg protein, neomycin, formaldehyde, tritonX-100, such as: Acute anaphylaxis, dyspnea, angioneurotic edema, etc., or allergies during previous vaccinations of the same kind; Patients with uncontrolled epilepsy and other serious neurological diseases (e.g., transverse myelitis, Guillain-Barre syndrome, demyelinating disease, etc.); Patients with acute diseases, or acute episodes of chronic diseases, or uncontrolled severe chronic diseases (such as hypertension that cannot be controlled by drugs, systolic blood pressure ≥160mmHg and/or diastolic blood pressure ≥100mmHg); Patients at the active stage of autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, sjogren's syndrome, etc.), patients with congenital or acquired immune deficiency, HIV infection with opportunistic infection or uncontrolled malignant tumor, lymphoma and leukemia; No spleen, or splenic operation history; Received immunomodulators within 6 months, such as immunosuppressive doses of glucocorticoids (dose reference: equivalent to prednisone 20mg/ day, over a week); Or monoclonal antibodies; Or thymosin; Or interferon; However, topical use (such as ointments, eye drops, inhalants or nasal sprays) is allowed; Has received blood or blood-related products, including immunoglobulin (including rabies immunoglobulin and tetanus immunoglobulin), within 3 months prior to experimental vaccine vaccination; Or planned use of the experimental vaccine within 1 month of vaccination; If subunit vaccine and inactivated vaccine are administered within 7 days prior to experimental vaccine inoculation, live attenuated vaccine shall be administered within 14 days prior to experimental vaccine inoculation; Lactating women or pregnant women (including women of childbearing age with positive urine pregnancy test); Those who have participated in or are participating in clinical trials related to COVID-19, or are participating in clinical trials of other drugs, or have received COVID-19 vaccines; The Investigator believes that the subject has any disease or condition that may place the subject at unacceptable risk; Subjects cannot meet the requirements of the program; Conditions that interfere with the assessment of vaccine response.