Inclusion Criteria:

- Aged 18 years and above.

- 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.

- Novel Coronavirus (COVID-19) Antibody (IgG and IgM) 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) infection or disease;

- History of COVID-19, or close contact with a confirmed/suspected COVID-19 patient,
or SARS-CoV-2 nucleic acid test was positive or antibody test (IgG, IgM) was
positive;

- Used antipyretic drugs, painkillers or anti-allergic drugs within 24 h before
enrollment;

- Has received COVID-19 vaccine;

- 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 during the 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. Known diagnosis of or having infectious diseases, or positive for any one of
HBsAg, anti-HCV antibody, anti-TP antibody or anti-HCV 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 (in the opinion of
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, in the opinion of the investigator, 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;