Table 2.
Anti-SARS-CoV-2 antibody responses of 4 vaccine groups at Day 1, Day 14, Day 28, and Day 84 post booster dose.
| SARS-CoV-2 S-IgG (BAU/mL) Geometric mean (95% CI) |
Geometric mean neutralization titer (NT50) (IU/mL) |
|||
|---|---|---|---|---|
| Alpha Variant | Delta Variant | |||
| Group 1 | Day 1 | 72.10 (60.06–86.56) | 8.73 | 1.07 |
| Day 14 | 194.07 (165.50–227.57) | 125.94 | 3.73 | |
| Day 28 | 170.09 (146.79–197.08) | 97.02 | 4.72 | |
| Day 84 | 88.96 (77.50–102.12) | 32.22 | 3.66 | |
| Group 2 | Day 1 | 76.38 (64.82–89.99) | 4.35 | 1.00 |
| Day 14 | 2330.81 (2038.83–2664.60) | 1237.61 | 274.55 | |
| Day 28 | 1534.82 (1350.72–1744.02) | 928.72 | 204.42 | |
| Day 84 | 517.36 (456.46–586.39) | 282.36 | 73.51 | |
| Group 3 | Day 1 | 93.47 (76.77–113.80) | 11.03 | 1.42 |
| Day 14 | 3283.76 (2905.02–3711.87) | 993.21 | 263.07 | |
| Day 28 | 1789.50 (1588.75–2015.62) | 510.66 | 89.81 | |
| Day 84 | 553.68 (494.20–620.31) | 180.98 | 35.01 | |
| Group 4 | Day 1 | 449.28 (383.46–526.40) | 51.13 | 2.41 |
| Day 14 | 3791.72 (3457.41–4158.35) | 1524.16 | 342.12 | |
| Day 28 | 2516.60 (2285.50–2771.06) | 961.98 | 195.36 | |
| Day 84 | 903.10 (813.62–1002.43) | 403.75 | 105.72 | |
BAU, binding antibody units; CI, confidence interval; NT50, 50% neutralization titer; IU, international unit.
Antibody values were transformed to log values, and the average values were expressed as geometric means with 95% confidence interval.