Immunogenicity and Safety Evaluation of Recombinant Novel Coronavirus Vaccine (CHO Cells) in Enhancing Immunity

Overall design: An open experimental design was adopted in this study, and 360 subjects were planned to be enrolled.To evaluate the immunogenicity and safety of recombinant Novel Coronavirus vaccine (CHO cells) after sequential booster immunization in populations vaccinated with two doses of marketed Novel Coronavirus inactivated vaccine. Intervention: This study involved people 18 years of age and older.All subjects recruited must have received two doses of Novel Coronavirus inactivated vaccine for 3 to 13 months (the interval between booster and basic immunization is divided into 3 groups:120 subjects at 3-4 months (91-120 days), 6-8 months (181-240 days) and 11-13 months (331-390 days) were vaccinated with one dose of recombinant Novel Coronavirus vaccine (CHO cells). Immunogenicity observation: Blood samples were collected from all subjects before and 14 days after experimental vaccine vaccination for humoral immunoassay. Safety observation: AE and SAE: Collect all adverse events (AE) at least 30 minutes after vaccination, all AE (both solicitation and non-solicitation AE) from 0 to 7 days, and all AE (non-solicitation AE) from 8 to 30 days;All serious adverse events (SAE) within 1 month after vaccination with the experimental vaccine were collected. 1. Solicitation AE (the following events occurring within 0-7 days after vaccination with experimental vaccine) :Adverse events at the inoculation site (local) : pain, itching, redness, swelling, rash, induration; Non-inoculated site (systemic) adverse events: fever, headache, fatigue/fatigue, diarrhea, nausea, vomiting, muscle pain (non-inoculated site), acute allergic reaction, cough. 2. Vital signs and physical examination:All subjects were assessed for vital signs (blood pressure, axillary body temperature, pulse) during screening and axillary body temperature before trial vaccination. All subjects underwent physical examination (skin, cardiopulmonary auscultation) during the screening period. 3. Collection of pregnancy events:Women of childbearing age should undergo a urine pregnancy test before enrollment (on the day of vaccination). Pregnancy events occurring within 1 month after trial vaccination were collected. 4. ADE/VED (Antibody enhancement/vaccine Enhancement) Risk Monitoring:After receiving the experimental vaccine, if the subject is diagnosed with COVID-19, he/she should go to the hospital for hospitalization or be isolated in accordance with the local epidemic prevention and control requirements.A special investigation will be conducted for severe/critical/fatal cases, and the existence of ADE/VED will be analyzed based on the results of the special investigation.