Participants
alcohol abuse, angioedema, allergic diseases
ACUTE FEBRILE ILLNESS, ANGIOEDEMA, ANAPHYLACTIC REACTION, CHRONIC DISEASES
Volunteer enrollment was managed via the study web-based software. They could read the informed consent and go through an initial self-administered screening questionnaire. Those who passed this stage were invited to attend the clinical trial centers for face-to-face screening by the study officers and signing the written informed consent form. People aged 18 or older were included. Major exclusion criteria were as follows: pregnancy and lactation; History of receiving Covid-19 vaccine; Close contact with a definite case of Covid-19 up to two weeks before the day of receiving the first dose; Acute febrile illness; Current acute or chronic symptomatic illness that requires ongoing medical or surgical care; History of allergic diseases such as angioedema or anaphylactic reactions following the use of drugs, vaccines or food; History of long-term use (14 successive days) of immunosuppressive drugs or systemic corticosteroids in the last four months leading up to the study; History of diagnosis or treatment for HIV; Current drug or alcohol abuse (addiction); Chronic diseases that are not listed as exclusion criteria but are considered unstable within the last four weeks. Detailed inclusion and exclusion criteria are provided in the protocol (for more details please see the protocol).