Procedures
ADVERSE EVENTS, DISEASE, SARS-COV-2 INFECTION
At six quarantine sites in the Yuzhong District, Chongqing, site investigation was carried out to screen eligible participants. Eligible participants were given the choice to join the A8G6 treatment group or blank control group. For eligible participants that showed “no preference” in either group, they were randomly assigned to A8G6 treatment group or blank control group. Oropharyngeal swabs were taken for quantitative and qualitative RT-PCR assessments at baseline prior to treatment and though the treatment period and a follow-up period. Subjects with positive RT-PCR results before treatment were excluded. The SARS-CoV-2 viral load was present by viral genome copies per mL log10 values with the conversion of the open reading frame of 1ab (ORF1ab) and nucleocapsid (N-gene) cycle threshold (Ct) values (RT-PCR was conducted by Yuzhong District Center for Disease Control and Prevention, in Chongqing, China. Conversion of Ct values to viral genome copies was calculated according to the manufacturer’s instructions of 2019-nCoV viral RNA kit produced by BioPerfectus Technologies, catalog number: JC10223-1N).Subjects’ demographic data, health and COVID-19 vaccination status were recorded at the baseline visit (Day 0). The use of nasal spray, rapid antigen tests or RT-PCR test for COVID-19 were recorded every day during the study participation. When participants in both groups were diagnosed with SARS-CoV-2 infection, the related symptoms and symptomatic treatment for COVID-19 were reported until the trial completed. In the treatment group, all participants were requested to self-report and record the adverse events. Due to the relaxation of COVID-19 control and policy starting from December 4, 2022, some participants returned to home for further isolation. The follow-up visits were adjusted to retrospective telephonic visit according to a questionnaire form from that day.