Table 1.
Geometric mean titer (GMT) and geometric mean fold rise (GMFR) for anti-SARAS-CoV2 spike protein receptor binding domain (S-RBD) antibodies and comparison between the Roche and Abbott assays.
| Number of vaccination | 1 | 2 | 3 | 4 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week after number of vaccination | 3 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 |
| Week after initial vaccination |
3 |
8 |
12 |
16 |
20 |
24 |
28 |
32 |
36 |
44 |
48 |
52 |
56 |
60 |
64 |
68 |
76 |
| Number of subjects | 16 | 16 | 15 | 15 | 15 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 15 | 15 | 15 | 12 |
| Roche S-RBD antibody | |||||||||||||||||
| GMT (BAU/mL) | 66 | 2134 | 1624 | 1463 | 1189 | 1049 | 915 | 766 | 686 | 31,104 | 20,470 | 12,662 | 9710 | 8092 | 6716 | 8092 | 23,834 |
| 95% CI | 39–170 | 1482–3073 | 1140–2316 | 1031–2076 | 817–1731 | 742–1485 | 661–1268 | 559–1049 | 498–946 | 19,534–49526 | 11,977–34985 | 7195–22284 | 5382–17516 | 4257–15380 | 3473–12986 | 4257–15,380 | 16,045–35,404 |
| GMFR | 32.41 | 0.70 | 0.90 | 0.81 | 0.92 | 0.87 | 0.84 | 0.90 | 45.33 | 0.66 | 0.62 | 0.77 | 0.79 | 0.83 | 0.88 | 5.53 | |
| 95% CI | 20.60–50.99 | 0.63–0.77 | 0.83–0.97 | 0.76–0.86 | 0.88–0.96 | 0.84–0.91 | 0.80–0.87 | 0.85–0.94 | 30.77–66.78 | 0.58–0.75 | 0.58–0.66 | 0.73–0.82 | 0.77–0.81 | 0.80–0.86 | 0.85–0.91 | 3.95–7.75 | |
| Abbott S-RBD antibody | |||||||||||||||||
| GMT (BAU/mL) | 168 | 2068 | 1103 | 633 | 388 | 262 | 196 | 156 | 134 | 3921 | 2565 | 1939 | 1503 | 1235 | 938 | 864 | 3798 |
| 95% CI | 110–255 | 1435–2980 | 750–1622 | 428–937 | 267–564 | 182–378 | 140–276 | 112–216 | 97–185 | 2562–6001 | 1556–4230 | 1148–3277 | 846–2668 | 657–2319 | 491–1794 | 439–1700 | 2636–5471 |
| GMFR | 12.34 | 0.50 | 0.57 | 0.61 | 0.71 | 0.75 | 0.79 | 0.86 | 29.20 | 0.65 | 0.76 | 0.77 | 0.82 | 0.76 | 0.92 | 6.12 | |
| 95% CI | 9.17–16.61 | 0.47–0.53 | 0.54–0.61 | 0.57–0.65 | 0.67–0.76 | 0.71–0.79 | 0.76–0.83 | 0.82–0.91 | 20.76–41.08 | 0.57–0.75 | 0.70–0.82 | 0.72–0.83 | 0.78–0.86 | 0.73–0.80 | 0.87–0.98 | 4.42–8.48 | |
| Comparison between Roche and Abbott antibody | |||||||||||||||||
| Roche/Abbott ratio, average | 0.46 | 1.13 | 1.60 | 2.46 | 3.25 | 4.23 | 4.92 | 5.14 | 5.32 | 8.10 | 8.26 | 6.78 | 6.71 | 6.72 | 7.36 | 7.10 | 6.42 |
| 95% CI | 0.29–0.63 | 0.89–1.36 | 1.26–1.95 | 2.02–2.89 | 2.62–3.87 | 3.46–5.00 | 3.98–5.87 | 4.20–6.09 | 4.44–6.20 | 7.29–8.91 | 7.16–9.35 | 5.82–7.73 | 5.84–7.60 | 5.76–7.66 | 6.34–8.39 | 6.05–8.14 | 6.05–8.14 |
| correlation coefficient | 0.93 | 0.70 | 0.72 | 0.83 | 0.83 | 0.82 | 0.76 | 0.81 | 0.84 | 0.99 | 0.94 | 0.94 | 0.97 | 0.96 | 0.95 | 0.92 | 0.95 |
| P value | <0.0001 | 0.0026 | 0.0023 | 0.0001 | 0.0001 | 0.0001 | 0.0007 | 0.0002 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Abbreviations: S-RBD, spike protein receptor binding domain; GMT, geometric mean titer; BAU, binding antibody units; CI, confidence interval; GMFR, geometric mean fold rise.
The correlation between the two antibody titers was determined by Pearson's correlational analysis.