A Phase III Clinical Trial to Determine the Safety and Efficacy of ZF2001 for Prevention of COVID-19

Inclusion Criteria:

- Population aged 18 years and above;

- Subjects voluntarily participate in the study and sign the informed consent form; and
are able to provide valid identification, and understand and comply with the
requirements of the trial protocol;

- Female subjects of childbearing age agree to use effective contraceptive measures from
the beginning of the study to 2 months after full course of vaccination.

Exclusion Criteria:

- Suspected or confirmed as fever(axillary temperature ≥37.3°C / oral temperature
≥37.5°C) within 72 hours before the enrollment, or axillary temperature ≥37.3°C / oral
temperature ≥37.5°C at the day of screening;

- Diastolic blood pressure ≥ 100mmhg and / or systolic blood pressure ≥ 150mmhg;

- Patients with previous history of a COVID-19;

- Detection of SARS-COV-2 nucleic acid or antibody is positive;

- Those who are suffering from the following diseases:

1. With thrombocytopenia, any coagulation dysfunction or receiving anti-coagulatory
treatment

2. Congenital or acquired immune deficiency or autoimmune disease history; no
spleen, or history of splenic surgery and trauma, or receiving immunomodulator
treatment within 6 months, e.g., immunosuppressive dose of glucocorticoids
(reference dose: equivalent to 20mg/ day of prednisone, over 1 week); Or
monoclonal antibodies; Or thymosin; Or interferon etc.; However, topical
application (such as ointment, eye drops, inhalers or nasal sprays) is permitted;

3. Symptoms related to acute respiratory tract infection (such as sneezing, nasal
congestion, runny nose, cough, sore throat, loss of taste, chills, shortness of
breath, etc.);

4. Cancer patients (except basal cell carcinoma).

- With a history of serious allergy to any vaccine or any composition of Investigational
product (including: aluminum preparations), such as allergic shock, allergic throat
edema, allergic purpura, thrombocytopenic purpura, localized allergic necrosis
reaction (Arthus reaction), dyspnea and angioneuroedema;

- Inoculated with subunit vaccine and inactivated vaccine within 14 days before the
first dosing of investigational vaccine, or inoculated with attenuated live vaccine
within 30 days;

- Previous receiving blood transfusion or blood relevant products (including
immunoglobulin) within 3 months, or planning to receive such products from the
starting of study to <6 months after the whole-course inoculation;

- Have participated in or are participating in other covid-19 related clinical trials;

- Women in breastfeeding period or in pregnant period (including women at childbearing
age with positive result of urine pregnancy test);

- Considered by investigators as any disease or state possibly making the subject at
unacceptable risk; not conforming to the requirements of study protocol; interference
of assessment of reactions of vaccine.