Fig. 5
Correlations between T/C ratios, Nab titers, and protection rates for 312 COVID-19 patients. T/C ratio is taken to indicate the total RBD-specific antibody level. The corresponding relation between -Log2(neutralizing titer) and neutralizing titer: 2 (1:4), 3 (1:8), 4 (1:16), 5 (1:32), 6 (1:64), 7 (1:128), 8 (1:256), 9 (1:512), 10 (1:1024). All patients were discharged from hospitals of Guangdong according to the criteria and quarantined for 14 days by Guangdong CDC. If the SARS-CoV-2 RNA test by PCR is positive in this period, the case is defined as recurrent-positive, namely, without protection. Linear (a) and Spearman (b) correlation between T/C ratios of UPT-POCT and NAb titers in 312 serum samples from COVID-19. Linear regression between the T/C ratios and accumulated recurrent positive rate (c) or protection rates against RP (d). The error bar for neutralizing titers ranging from 1:4 to 1:512 or 1:1024 is derived from the detection results for 15, 32, 44, 77, 41, 57, 27, 11, and 8 samples, respectively