Participants
thrombocytopenia, allergic
THROMBOCYTOPENIA, COAGULATION DISORDERS, CHRONIC DISEASE
Eligible trial subjects were healthy men and nonpregnant women, aged 18 years or above, who had previously vaccinated with two or three doses of BBIBP-CorV at least 6 months prior to enrollment. All participants signed an informed consent form. During screening, healthy status of each volunteer was assessed by inquiry and physical examination. Volunteers who had previously received any other COVID-19 vaccine instead of the BBIBP-CorV were excluded. Individuals whose axillary temperature ≥37.3 °C (or forehead temperature ≥37.8 °C) or allergic to any components of the vaccine were also excluded. Other exclusion criteria included history of thrombocytopenia or other coagulation disorders; immunological impairment or immunocompromise; receipt of any blood products or immunoglobulin therapy within 3 months prior to enrollment; serious chronic disease; receipt of any other inactivated vaccines in the past 14 days, or any live attenuated vaccines post one month; receipt of any investigational drugs within 6 months prior to enrollment; and other vaccination-related contraindications considered by the investigator.