Clinical Trial to Evaluate the Efficacy, Immunogenicity and Safety of the Inactivated SARS-CoV-2 Vaccine (COVID-19)

Inclusion Criteria: * Healthy subjects aged between 18 and 85 years old. * By asking for medical history and physical examination, the investigator judged that the health condition is well. * Female subjects of childbearing age are not nursing or pregnant at the time of enrolment (negative urine pregnancy test) and have no family planning within the first 3 months after enrolment. Effective contraceptive measures have been taken within 2 weeks before inclusion. * During the whole follow-up period of the study, be able and willing to complete the whole prescribed study plan. * With self-ability to understand the study procedures, the informed consent \& voluntarily sign an informed consent form and be able to comply with the requirements of the protocol. Exclusion Criteria: * Active Sars-Cov-2 Infection measured by RT-qPCR * Has a history of SARS, MERS infection (self-report, on-site inquiry) * Has clinical manifestation of fever (axillary temperature \> 37.0 ℃), dry cough, fatigue, nasal obstruction, runny nose, pharyngeal pain, myalgia, diarrhea, shortness of breath and dyspnea occurred within 14 days before vaccination. * Body temperature \> 37.0 ℃ before vaccination * Urine pregnancy test positive; * Previous severe allergic reactions to vaccination (such as acute allergic reactions, urticaria, dyspnea, angioneurotic edema or abdominal pain) or allergy to known ingredients of inactivated SARS-CoV-2 vaccine have occurred. * Has a history of convulsion, epilepsy, encephalopathy or mental illness or family history. * With congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc. * With severe liver and kidney diseases, uncontrollable hypertension (systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg), diabetic complications, malignant tumors, various acute diseases, or acute attack period of chronic diseases. * Has been diagnosed with congenital or acquired immune deficiency, HIV infection, lymphoma, leukemia, or other autoimmune diseases. * With known or suspected diseases include severe respiratory diseases, severe cardiovascular diseases, liver and kidney diseases, and malignant tumors. * Has a history of coagulation dysfunction (e.g. Coagulation factor deficiency, coagulation disease) * Receiving anti-TB therapy. * Patients receiving immunotherapy or inhibitor therapy within 3 months (continuous oral or infusion for more than 14 days) * Inoculated live attenuated vaccines within 1 month before this vaccination, other vaccines are inoculated within 14 days before this vaccination. * Received blood products within 3 months before this vaccination * Received other research drugs within 6 months before this vaccination. * Other circumstances judged by investigators that are not suitable for this clinical trial.