Table 2.
Summary of pre-calibration ID50 and ID80 titers measured by the Duke and Monogram labs and their fold-differences for convalescent patient sera, Day 29 vaccinee sera, Day 57 vaccinee sera, and the WHO International Standard sample.
| Convalescent (n = 248) | Vaccine Day 29 (n = 30) | Vaccine Day 57 (n = 30) | Vaccine Day 57 versus Day 29 | WHO International Standard | |
|---|---|---|---|---|---|
| ID50 | |||||
| Duke | |||||
| Mean (SD)* | 607.3 (1.6) | 65.7 (0.8) | 1463.5 (1.1) | 22.3 (1.1) | 3046.7 (0.8) |
| Median | 581.0 | 72.5 | 1547.0 | 22.4 | 2421.5 |
| Range | 23.0–32,362.0 | 13.0–456.0 | 15.0–4714.0 | 0.5 – 158.4 | 957.0–11,101.0 |
| Response Rate** | 99% | 100% | 100% | NA | 100% |
| Monogram | |||||
| Mean (SD)* | 1692.0 (1.4) | 178.3 (1.0) | 4120.7 (1.0) | 23.1 (1.1) | 14,997.5 (0.2) |
| Median | 1604.0 | 219.5 | 5274.0 | 23.5 | 16,133.0 |
| Range | 72.0–100,563.0 | 20.0–1222.0 | 62.0–16,280.0 | 0.4 – 163.2 | 10,044.0–21,785.0 |
| Response Rate** | 100% | 90% | 100% | NA | 100% |
| Monogram versus Duke fold difference | |||||
| Mean (SD)* | 2.8 (0.7) | 2.7 (0.4) | 2.8 (0.4) | NA | 4.9 (NA) |
| Median | 3.0 | 2.8 | 2.7 | 6.7 | |
| Range | 0.3–26.0 | 1.0–7.1 | 1.2–6.3 | 2.0–10.5 | |
| ID80 | |||||
| Duke | |||||
| Mean (SD)* | 103.7 (1.6) | 16.2 (0.8) | 330.5 (0.9) | 20.3 (0.9) | 566.7 (0.6) |
| Median | 94.5 | 19.5 | 421.5 | 22.7 | 489.0 |
| Range | 10.0–5078.0 | 5.0–91.0 | 5.0–1255.0 | 1.0–112.0 | 250.0–1391.0 |
| Response Rate** | 83% | 77% | 97% | NA | 100% |
| Monogram | |||||
| Mean (SD)* | 536.8 (1.4) | 60.9 (0.8) | 1522.5 (1.0) | 25.0 (1.1) | 4259.7 (0.2) |
| Median | 504.5 | 82.0 | 1758.5 | 27.5 | 4062.5 |
| Range | 20.0–32,557.0 | 20.0–393.0 | 20.0–5984.0 | 0.5–130.5 | 2950.0–6892.0 |
| Response Rate** | 98% | 70% | 97% | NA | 100% |
| Monogram versus Duke fold difference | |||||
| Mean (SD)* | 5.2 (0.7) | 3.7 (0.5) | 4.6 (0.2) | NA | 7.5 (NA) |
| Median | 5.1 | 4.0 | 4.5 | 8.3 | |
| Range | 0.4–75.2 | 1.3–15.0 | 2.9–7.8 | 5.0–11.8 | |
*Geometric mean of titers or titer ratios and standard deviation of the loge-transformed titers or titer ratios.
**Proportion of samples with an ID50 or ID80 titer above the assay LLoD.