Table 1. Serologic Data of 769 Serum Samples Obtained From 659 Individuals With Confirmed COVID-19 Among Different Age Classes, Overall and Stratified by Time From Baselinea.
| Variable | Anti-RBD, median (IQR), kBAU/L | |||
|---|---|---|---|---|
| All data | 1-4 mo from onset | 5-9 mo from onset | >10 mo from onset | |
| Age class, y | ||||
| <3 | 304.83 (139.0-519.6) | 342.8 (179.5-519.6) | 284.3 (162.5-519.6) | 146.2 (62.8-231.2) |
| ≤3 | 169.3 (103.1-277.1) | 234.6 (113.5-347.9) | 118.2 (70.6-192.5) | 115.6 (45.9-160.6) |
| ≤6 | 126.2 (74.0-207.8) | 164.1 (79.1-236) | 119.7 (77.4-165.2) | 90.6 (62.4-111.8) |
| ≤12-18 | 98.2 (44.7-169.0) | 103.1 (46.3-170.2) | 89.6 (45.9-170.2) | 48.6 (18.1-95.7) |
| ≥18 | 55.6 (24.2-136.0) | 64.5 (26.2-140.9) | 49.8 (22.5-114.7) | 36.7 (13.5-108.5) |
| P valueb | <.001 | <.001 | <.001 | .02 |
Abbreviations: kBAU/L, kilo–binding antibody units per liter; RBD, receptor-binding domain.
a
Serum samples at the last time point for 17 people whose last S-RBD IgG titer was higher than the previous one were excluded from the analysis.
b
Kruskal-Wallis test.