Immunogenicity and Safety of a Third Dose of COVID-19 Vaccine(Vero Cell), Inactivated in the Elderly
COVID-19
About this trial
This is an interventional prevention trial for COVID-19
Eligibility Criteria
Inclusion Criteria:
- Subjects aged 60 years and above;
- Provide legal identification;
- Have completed two-dose of COVID-19 vaccine (Vero cell), inactivated manufactured by Sinovac Research& Development Co., Ltd. for 3~6 months(The interval between two doses was 21~35 days);
- Be able to understand and voluntarily sign the informed consent form and be willing to complete the study according to the research plan.
Exclusion Criteria:
- History of SARS-CoV-2 infection(laboratory confirmed);
- Those who have received COVID-19 vaccine from other manufacturers other than Sinovac Research& Development Co., Ltd., or who have received booster immunization with COVID-19 vaccine after two doses of COVID-19 vaccine (Vero cell),inactivated manufactured by Sinovac Research& Development Co., Ltd.;
- History of serious adverse reactions to the vaccine or vaccine components, such as urticaria dyspnea and angioneuroedema;
- Autoimmune disease or immunodeficiency/immunosuppression;
- Severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc;
- Severe neurological disease (epilepsy, convulsions or convulsions) or mental illness;
- Immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids(excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months or plan to receive these treatments during the study period;
- Receipt of blood products within in the past 3 months or plan to receive these treatments during the study period;
- Receipt of other investigational drugs in the past 30 days;
- Receipt of attenuated live vaccines in the past 14 days,or receipt of inactivated or subunit vaccines in the past 7 days;
- Onset of various acute or chronic diseases within 7 days prior to the study;
- Axillary temperature >37.0°C;
- According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.
Sites / Locations
- Yongde Center for Diseases Control and Prevention
Arms of the Study
Arm 1
Arm 2
Arm 3
Arm 4
Experimental
Experimental
Experimental
Experimental
Experimental group 1 (3-month interval)
Experimental group 2 (4-month interval)
Experimental group 3 (5-month interval)
Experimental group 4 (6-month interval)
100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (3-month interval).
100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (4-month interval).
100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (5-month interval).
100 subjects who have received two doses of COVID-19 vaccine (Vero cell), Inactivated will receive a 3rd dose of the vaccine (6-month interval).