a decreasing trendp <0.001
Real time RT-PCR detection of SARS-CoV-2 genomes in respiratory tract samples showed a decreasing trend over time ( Fig. 6A , ANOVA repeated measures p <0.001), whereas virus-specific serum IgG antibody levels, measured by RBD ELISA, showed a significant increase ( Fig. 6B , ANOVA repeated measures, p <0.001).