Table 3.
SARS-CoV-2 RBD-binding IgG antibody measured by enzyme-linked immunosorbent assay (ELISA) (per-protocol set).
| GBP510/AS03 (N = 877) | ChAdOx1-S (N = 441) | |
|---|---|---|
| Baseline | ||
| n | 877 | 441 |
| GMT (SD) | 10.91 (1.75) | 10.79 (1.70) |
| 95% Confidence Interval | [10.51, 11.32] | [10.27, 11.34] |
| Ratio of GMTs (GBP510/ChAdOx1-S) (SD) | 1.01 (1.74) | |
| 95% Confidence Interval | [0.95, 1.08] | |
| p-valuea | 0.74 | |
| Visit 4 (4 weeks after 1st vaccination) | ||
| n | 877 | 441 |
| GMT (SD) | 171.73 (2.28) | 119.46 (2.42) |
| 95% Confidence Interval | [162.58, 181.40] | [109.98, 129.75] |
| Ratio of GMTs (GBP510/ChAdOx1-S) (SD) | 1.44 (2.33) | |
| 95% Confidence Interval | [1.30, 1.58] | |
| p-valuea | <0.0001 | |
| GMFR(SD) | 15.74 (2.57) | 11.07 (2.72) |
| 95% Confidence Interval | [14.79, 16.76] | [10.08, 12.15] |
| Adjusted GMT (SE) | 131.24 (1.06) | 91.91 (1.06) |
| 95% Confidence Interval | [117.90, 146.09] | [81.55, 103.57] |
| Ratio of GMTs (GBP510/ChAdOx1-S) (SE) | 1.43 (1.05) | |
| 95% Confidence Interval | [1.30, 1.57] | |
| p-valueb | <0.0001 | |
| Participants with ≥4-fold rise, n (%) | 811 (92.47) | 374 (84.81) |
| 95% Confidence Interval | [90.52, 94.13] | [81.11, 88.03] |
| Difference in Proportions of the Participant with ≥4-fold rise | 7.67 | |
| 95% Confidence Interval | [3.89, 11.44] | |
| p-valuec | <0.0001 (c) | |
| Visit 6 (2 weeks after 2nd vaccination) | ||
| n | 877 | 441 |
| GMT(SD) | 3230.35 (2.10) | 248.45 (2.23) |
| 95% Confidence Interval | [3074.90, 3393.67] | [230.46, 267.84] |
| Ratio of GMTs (GBP510/ChAdOx1-S) (SD) | 13.00 (2.15) | |
| 95% Confidence Interval | [11.91, 14.19] | |
| p-valuea | <0.0001 | |
| GMFR(SD) | 296.10 (2.57) | 23.02 (2.48) |
| 95% Confidence Interval | [278.11, 315.24] | [21.14, 25.06] |
| Adjusted GMT(SE) | 2850.45 (1.05) | 215.67 (1.06) |
| 95% Confidence Interval | [2586.51, 3141.32] | [193.52, 240.36] |
| Ratio of GMTs (GBP510/ChAdOx1-S) (SE) | 13.22 (1.04) | |
| 95% Confidence Interval | [12.13, 14.40] | |
| p-valueb | <0.0001 | |
| Participants with ≥4-fold rise, n (%) | 873 (99.54) | 427 (96.83) |
| 95% Confidence Interval | [98.84, 99.88] | [94.73, 98.25] |
| Difference in Proportions of the Participant with ≥4-fold rise | 2.72 | |
| 95% Confidence Interval | [1.02, 4.41] | |
| p-valuec | <0.0001 (c) | |
GMT = geometric mean titer, SD = standard deviation, SE = standard error, GMFR = geometric mean fold rise, ANCOVA = analysis of covariance.
Assay unit: BAU/mL.
GMT = anti-logarithm [mean of natural logarithm (titre at visit n)], GMFR = anti-logarithm [mean of natural logarithm (titre at visit n/titre at visit 2)].
95% confidence intervals for GMT and GMFR are calculated using Wald method with t-distribution.
The 95% CI of percentage of participants ≥ 4-fold rises is calculated based on Clopper-Pearson method.
The 95% CI of the difference in percentage of participants ≥ 4-fold rises between groups was calculated based on Wald method.
Testing for difference between treatment groups (two sample t-test).
ANCOVA model with treatment group, age group (18∼64, ≥65) as factors, and baseline antibody level as covariate.
Testing for difference between treatment groups (chi-square test (c) or Fisher's exact test (f)).