Table 4.
Anti-SARS-CoV-2 activity of IgG fractions eluted from day-28, 60, 90, and 150 sera of high and moderate responders against VOCs and VUM.
| Strain/variant | Wuhan/SARS-CoV-205-2N | Alpha/SARS-CoV-2QHN-001 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Days from 1st dose | Day-28 | Day-60 | Day-90 | Day-28 | Day-60 | Day-90 | |||
| (A) | |||||||||
| Average EC50 (μg/ml) | High responder’s IgG | 4.3 ± 1.3 | 9.8 ± 5.3 | 13.7 ± 3.6 | 21.4 ± 5.9 | 23.9 ± 9.4 | 44.9 ± 15.4 | ||
| Moderate responder’s IgG | 6.9 ± 3.5 | 22.5 ± 8.2 | 36.2 ± 10.9 | 30.7 ± 11.7 | 43.0 ± 17.4 | 104.9 ± 31.3 | |||
| Fold changes* | High responder’s IgG | – | 2.3 | 3.2 | – | 1.1 | 2.1 | ||
| Moderate responder’s IgG | – | 3.3 | 5.3 | – | 1.4 | 3.4 | |||
| Moderate/high ratio | 1.6 | 2.3 | 2.7 | 1.4 | 1.8 | 2.3 | |||
| Mean of fold change** | High responder’s IgG | – | 2.3 | 3.4 | – | 1.2 | 2.1 | ||
| Moderate responder’s IgG | – | 3.6 | 5.8 | – | 1.5 | 3.8 | |||
| Difference (95% CI) | – | − 1.25 (− 2.43, − 0.07) | − 2.44 (− 3.76, − 1.12) | – | − 0.33 (− 0.73, 0.07) | − 1.68 (− 2.65, − 0.71) | |||
| p value | – | 0.039 | 0.001 | – | 0.1 | 0.002 | |||
| Variant | Alpha/SARS-CoV-2QK002 | Beta/SARS-CoV-2TY8-612 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Days from 1st dose | Day-28 | Day-60 | Day-90 | Day-28 | Day-60 | Day-90 | |||
| Average EC50 (μg/ml) | High responder’s IgG | 14.4 ± 6.6 | 24.7 ± 6.1 | 27.2 ± 6.1 | 60.8 ± 20.4 | 77.0 ± 22.1 | 92.6 ± 28.0 | ||
| Moderate responder’s IgG | 26.0 ± 12.8 | 58.3 ± 27.2 | 104.3 ± 33.2 | 90.8 ± 38.1 | 135.9 ± 37.3 | 189.3 ± 31.2 | |||
| Fold changes* | High responder’s IgG | – | 1.7 | 1.9 | – | 1.3 | 1.5 | ||
| Moderate responder’s IgG | – | 2.2 | 4 | – | 1.5 | 2.1 | |||
| Moderate/high ratio | 1.8 | 2.4 | 3.8 | 1.5 | 1.8 | 2 | |||
| Mean of Fold change** | High responder’s IgG | – | 2.3 | 2.5 | – | 1.4 | 1.7 | ||
| Moderate responder’s IgG | – | 2.5 | 4.7 | – | 1.8 | 2.6 | |||
| Difference (95% CI) | – | − 0.21 (− 1.36 , 0.94) | − 2.11 (− 3.7, − 0.53) | – | − 0.44 (− 1.06, 0.18) | − 0.94 (− 1.87, − 0.02) | |||
| p value | – | 0.708 | 0.011 | – | 0.159 | 0.047 | |||
| Variant | Gamma/SARS-CoV-2TY7-501 | Delta/SARS-CoV-2K1734 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Days from 1st dose | Day-28 | Day-60 | Day-90 | Day-28 | Day-60 | Day-90 | |||
| Average EC50 (μg/ml) | High responder’s IgG | 30.3 ± 7.8 | 33.6 ± 10.7 | 57.4 ± 7.1 | 10.3 ± 5.6 | 25.2 ± 4.7 | 22.0 ± 5.6 | ||
| Moderate responder’s IgG | 48.2 ± 20.2 | 92.7 ± 30.5 | 124.6 ± 36.8 | 31.8 ± 12.6 | 46.7 ± 19.9 | 65.9 ± 23.1 | |||
| *Fold changes | High responder’s IgG | – | 1.1 | 1.9 | – | 2.5 | 2.1 | ||
| Moderate responder’s IgG | – | 1.9 | 2.6 | – | 1.5 | 2.1 | |||
| Moderate/high ratio | 1.6 | 2.8 | 2.2 | 3.1 | 1.9 | 3.0 | |||
| Mean of fold change | High responder’s IgG | – | 1.2 | 2 | – | 3.4 | 3.3 | ||
| Moderate responder’s IgG | – | 2 | 2.8 | – | 1.5 | 2.2 | |||
| Difference (95% CI) | – | − 0.82 (− 1.18, − 0.46) | − 0.83 (− 1.51, − 0.14) | – | 1.95 (0.65, 3.25) | 1.02 (− 0.57, 2.62) | |||
| p value | – | < 0.001 | 0.02 | – | 0.005 | 0.198 | |||
| Variant | Kappa/SARS-CoV-2K5356 | E484K/SARS-CoV-2F-76107 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Days from 1st dose | Day-28 | Day-60 | Day-90 | Day-28 | Day-60 | Day-90 | |||
| Average EC50 (μg/ml) | High responder’s IgG | 20.1 ± 6.3 | 25.6 ± 7.2 | 62.1 ± 31.2 | 19.2 ± 5.9 | 23.9 ± 5.0 | 21.9 ± 6.1 | ||
| Moderate responder’s IgG | 51.0 ± 17.9 | 78.8 ± 17.1 | 124.1 ± 31.0 | 36.0 ± 13.0 | 50.1 ± 19.2 | 64.9 ± 16.5 | |||
| Fold changes* | High responder’s IgG | – | 1.3 | 3.1 | – | 1.2 | 1.1 | ||
| Moderate responder’s IgG | – | 1.5 | 2.4 | – | 1.4 | 1.8 | |||
| Moderate/high ratio | 2.5 | 3.1 | 2 | 1.9 | 2.1 | 3 | |||
| Mean of fold change** | High responder’s IgG | – | 1.4 | 3.4 | – | 1.4 | 1.3 | ||
| Moderate responder’s IgG | – | 1.7 | 2.8 | – | 1.4 | 2 | |||
| Difference (95% CI) | – | − 0.33 (− 0.8, 0.14) | 0.61 (− 0.9, 2.11) | – | − 0.06 (− 0.45, 0.33) | − 0.71 (− 1.23, − 0.19) | |||
| p value | – | 0.157 | 0.412 | – | 0.757 | 0.01 | |||
| Strain/variant | Wuhan/SARS-CoV-205-2N | Delta/SARS-CoV-2K1734 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Days from 1st dose | Day-28 | Day-60 | Day-90 | Day-150 | Day-28 | Day-60 | Day-90 | Day-150 | |
| (B) | |||||||||
| Average EC50 (μg/ml) | High responder’s IgG | 4.3 ± 1.3 | 9.8 ± 5.3 | 13.7 ± 3.6 | 21.8 ± 5.5 | 10.3 ± 5.6 | 25.2 ± 4.7 | 22.0 ± 5.6 | 30.1 ± 6.4 |
| Moderate responder’s IgG | 6.9 ± 3.5 | 22.5 ± 8.2 | 36.2 ± 10.9 | 55.4 ± 18.5 | 31.8 ± 12.6 | 46.7 ± 19.9 | 65.9 ± 23.1 | 77.8 ± 11.0 | |
| Fold changes* | High responder’s IgG | – | 2.3 | 3.2 | 5.1 | – | 2.5 | 2.1 | 2.9 |
| Moderate responder’s IgG | – | 3.3 | 5.3 | 8.0 | – | 1.5 | 2.1 | 2.4 | |
| Moderate/high ratio | 1.6 | 2.3 | 2.7 | 2.5 | 3.1 | 1.9 | 3.0 | 2.6 | |
| Mean of fold change** | High responder’s IgG | – | 2.3 | 3.4 | 5.4 | – | 3.4 | 3.3 | 4.3 |
| Moderate responder’s IgG | – | 3.6 | 5.8 | 9.0 | – | 1.5 | 2.2 | 2.8 | |
| Difference (95% CI) | – | − 1.25 (− 2.43, − 0.07) | − 2.44 (− 3.76, − 1.12) | − 3.60 (− 6.25, − 0.96) | – | 1.95 (0.65, 3.25) | 1.02 (− 0.57, 2.62) | 1.53 (− 0.45, 3.51) | |
| p value | – | 0.039 | 0.001 | 0.01 | – | 0.005 | 0.198 | 0.123 | |
Average EC50 values of IgG fraction eluted from sera of high (n = 13) or moderate (n = 12) responders, taken on day-28, -60, -90, and -150 post 1st vaccine doses, are indicated.
*Fold change of EC50 values compared to that of day-28 IgG.
**Mean of fold change was calculated by arithmetic mean of each participant’s fold change at day-60, -90, and -150 against day-28. The difference between high and moderate responders using Student’s t-test.