TABLE 3.
Incidence rate of positive RT‐qPCR testing and serum neutralizing activity depending on SARS‐CoV‐2 RBD IgG levels
| SARS‐CoV‐2 RBD IgG levels, AU/ml a | p value | ||||
|---|---|---|---|---|---|
| <50 | 51–1050 | 1051–4160 | >4160 | ||
| RT‐qPCR testing result, n (%) | n = 12 | n = 97 | n = 82 | n = 80 | .01 |
| Positive | 5 (41.67) 7 (58.33) | 22 (22.68) | 15 (18.29) | 7 (8.75) | |
| Negative | 5 (41.67) 7 (58.33) | 75 (77.32) | 67 (81.71) | 73 (91.25) | |
| Serum micro‐neutralization titer against SARS‐CoV−2 wild type, median (IQR)[range] b |
n = 3 0 (0–0) [0–0] |
n = 10 0 (0–0) [0–0] |
n = 10 10.0 (0–10) [0–20] |
n = 5 160 (40–320) [20–640] |
.005 |
| Serum neutralization against SARS‐CoV−2 B.1.1.7 (VOC α), median (IQR)[range] b |
n = 3 0 (0–0) [0–0] |
n = 10 0 (0–0) [0–0] |
n = 10 10.0 (10–20) [0–40] |
n = 5 320 (80–640) [40–640] |
.005 |
a
Analysis using the Fisher exact test.
b
Analysis using the Kruskal‐Wallis test; micro‐neutralization titers are expressed as the serial dilution for which 50% neutralization is obtained.