Immunogenicity and Safety of COVID-19 Vaccine in Population Aged 18 Years and Above

Inclusion Criteria: * People aged 18 years and above who have not received COVID-19 vaccine or whose last vaccination was at least 6 months ago (at the time of screening). * Participate the trial voluntarily and sign informed consent form. * Subjects are willing to comply with the requirements of the clinical trial protocol and complete the study follow-up. * Armpit temperature ≤37.0℃ on the day of enrollment. * 2019 Novel Coronavirus (COVID-19) Antibody was negative. Exclusion Criteria: * Known allergy to investigational vaccine or its excipients, or previous history of anaphylactic shock or other serious adverse reactions to other vaccines * History of severe acute respiratory syndrome (SARS) and/or Middle East respiratory syndrome (MERS) or COVID-19 infection or disease; * Used antipyretic drugs, painkillers or anti-allergic drugs within 24 h before enrollment; * vaccination of subunit vaccines and/or inactivated vaccines within 7 days before enrollment, or vaccination of live attenuated vaccines within 14 days before enrollment; * Administration of blood or blood related products (including immunoglobulins) within 3 months before enrollment; or plan to use duringthe trial; * Patients with the following diseases: 1. Any acute disease or in the acute phase of chronic diseases within 7 days before enrollment; 2. Congenital malformation or developmental disorder, genetic defect, severe malnutrition, etc.; 3. History of congenital or acquired immunodeficiency or autoimmune diseases, or long-term(used continuously\>14 days)use of glucocorticoid (dose ≥ 20 mg/day prednisone or equivalent dose) or other immunosuppressants within the last 6 months, yet the following situations are allowed to be included: inhaled or topical use of external steroids, or short-term use (course ≤ 14 days ) of oral corticosteroids; 4. Positive for anti-AIDS antibody; 5. Neurological diseases or family history (convulsion, epilepsy, encephalopathy, etc.); history of psychosis or family history; 6. Asplenia or functional asplenia; 7. Serious or uncontrollable cardiovascular diseases, diabetes,hematological and lymphatic diseases, immune system diseases,liver and kidney diseases, respiratory diseases, metabolism and bone diseases, or malignant tumors that need hospitalization; 8. Contraindications of intramuscular injection and blood drawing,such as coagulation dysfunction, thrombosis or hemorrhagic diseases, or any condition that needs continuous use of anticoagulant; 9. Severe hypertension with uncontrolled medication (at field measurement: systolic blood pressure ≥160mmHg and/or diastolic blood pressure ≥100mmHg) . * History of major surgery within 12 weeks before enrollment (judged by the investigator), or incomplete recovery after surgery, or planning major surgery during the trial; * Participating or will participate other clinical trials during this trial; * Any disease or condition that would pose an unacceptable risk to the subject; the subject is unable to meet the protocol requirement; will interfere with evaluation of investigational vaccine. * Women who were breastfeeding or pregnant during the clinical study or planned to become pregnant during the study;