A Phase Ⅱ Clinical Trial of Recombinant Corona Virus Disease-19 (COVID-19) Vaccine (Sf9 Cells)

This is a phase Ⅱ, single-center, randomized, double-blind, placebo-controlled study, to evaluate the immunogenicity and safety of the recombinant COVID-19 vaccine (Sf9 cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-60 and 60-85 years) with different immunization procedures (0, 21 days and 0, 14, 28 days) and doses (20μg/40μg).

This is a phase Ⅱ, single-center, randomized, double-blind, placebo-controlled study, to evaluate the immunogenicity and safety of the recombinant COVID-19 vaccine (Sf9 cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-60 and 60-85 years) . The phase Ⅱ clinical trials designed 8 research group, including two immunization procedures (0, 21 days and 0, 14, 28 days), two doses (20μg/0.5ml, 40μg/1.0ml) and two ages group (adults and elder): Each group including 120 participants. Vaccination or placebo group will be randomly assigned to receive in a 5:1 ratio, 960 in total.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18 years and above.
* Able to understand the content of informed consent and willing to sign the informed consent.
* Able and willing to complete all the secluded study process during the whole study follow-up period (about 7 months).
* Axillary temperature ≤37.0℃.
* General good health as established by medical history and physical examination.

Exclusion Criteria:

First dose exclusion criteria:

* Positive serum immunoglobulin M (IgM) and IgG to the SARS-CoV-2.
* A Known History of HIV infection
* Family history of seizure, epilepsy, brain or mental disease.
* Participant that has an allergic history to any ingredient of vaccines.
* Woman who is pregnant, breast-feeding or positive in pregnancy test on day of enrollment, or is planning to be pregnant during the next 6 months.
* Any acute fever disease or infections.
* Have a medical history of SARS.
* Have serious cardiovascular diseases, such as arrhythmia, conduction block, myocardial infarction, severe hypertension and not well-controlled.
* Major chronic illness, such as asthma, diabetes, or thyroid disease, and not well-controlled.
* Hereditary angioneurotic edema or acquired angioneurotic edema.
* Urticaria in last one year.
* Asplenia or functional asplenia.
* Platelet disorder or other bleeding disorder may cause injection contraindication.
* Faint at the sight of blood or needles.
* Prior administration of immunodepressant or corticosteroids, antianaphylactics treatment, cytotoxic treatment in last 6 months.
* Prior administration of blood products in last 4 months.
* Prior administration of other research medicines in last 1 month.
* Prior administration of attenuated vaccine in last 1 month.
* Prior administration of subunit vaccine or inactivated vaccine in last 14 days.
* Being treated for tuberculosis.
* Any condition that in the opinion of the investigators may interfere with the evaluation of study objectives.

Exclusion criteria for subsequent doses:

* Patients with severe allergic reactions after the previous dose of vaccination;
* Patients with serious adverse events causally related to the previous dose of vaccination.