inclusion criteria: - have not received any covid-19 vaccine in the past or at least one dose of coronavac manufactured by sinovac research and development co.,ltd; - population aged 18 years and above; - the subjects can understand and voluntarily sign the informed consent form and participate in the follow-up;

inclusion criteria: - have not received any covid-19 vaccine in the past or at least one dose of coronavac manufactured by sinovac research and development co.,ltd; - population aged 18 years and above; - the subjects can understand and voluntarily sign the informed consent form and participate in the follow-up;