Recombinant Omicron-Delta COVID-19 Vaccine (CHO Cell)

Inclusion Criteria: 1. At the time of signing the Informed Consent, he was 18 years old or above; 2. Normal body temperature (axillary temperature \< 37.3 ℃/oral temperature \< 37.5 ℃); 3. Meet one of the following conditions: 1) 6-15 months after the basic immunization (2 injections) of the inactivated vaccine of the prototype strain of COVID-19-19 has been completed; 2) 6-9 months after the booster immunization (3 injections) of the inactivated vaccine of the prototype strain of COVID-19 has been completed; 3) 6-15 months after basic immunization (3 injections) of recombinant vaccine of COVID-19 prototype strain has been completed. 4. The vaccines used to complete the above basic immunization or enhanced immunization were produced by Beijing Biotech, Wuhan Biotech, Sinovac and Zhifeilong Koma, and the same kind of vaccine was inoculated throughout the whole process. 5. Female subjects over 18 years old were not pregnant (blood pregnancy test was negative), were not in lactation and took effective contraceptive measures within 4 weeks after inoculation; The male subject must agree to take effective contraceptive measures by himself and his partner within 4 weeks after signing the informed consent and vaccination. 6. Subjects have the ability to understand the research procedure, voluntarily sign the informed consent form after informed consent, can comply with the requirements of the clinical research protocol, and can and is willing to complete the entire required research plan. Exclusion Criteria: 1. A history of serious allergy to any vaccine in the past, or a history of serious allergy to any component of the studied vaccine, including aluminum preparations, such as anaphylactic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, dyspnea, angioneurotic edema, allergic constitution (such as allergic to two or more drugs, food or pollen); 2. Confirmed cases of novel coronavirus infection, asymptomatic infections or positive history of novel coronavirus nucleic acid testing; 3. Patients with uncontrollable lymphoproliferative disease, aplastic anemia, primary immune thrombocytopenia (ITP), and haemorrhagic disease; 4. A history of congenital or acquired immunodeficiency or autoimmune diseases; 5. The life expectancy of patients with malignant tumors is less than 1 year; 6. Patients with uncontrolled epilepsy and other progressive nervous system diseases (such as transverse myelitis, Guillain Barre syndrome, demyelinating disease, etc.); 7. Patients with acute disease, or acute attack period of chronic disease, or uncontrolled severe chronic disease, such as hypertension beyond the control of drugs (systolic blood pressure ≥ 150 mmHg and/or diastolic blood pressure ≥ 100 mmHg); 8. Those who have received inactivated vaccine within one week or attenuated vaccine within four weeks before vaccination; 9. Subjects who have participated in other clinical studies or are participating in other clinical studies within 3 months; 10. The investigator believes that the subject has any disease or condition that may put the subject at risk, that the subject cannot complete the study as required by the protocol, and that there are conditions that interfere with the evaluation of vaccine response.