Table 2.
Hazard ratio for COVID-19 as nAb marker values increase.
| Time point | Antibody marker* | No. cases/no. at-risk† | Hazard ratio | Point estimate | (95% CI) | P value (two-sided) | FDR-adjusted P value‡ | FWER-adjusted P value |
|---|---|---|---|---|---|---|---|---|
| D29 | LV-MN50 (IU50/ml) |
55/14,141 | Per 10-fold increase | 0.39 | (0.19, 0.83) | 0.014 | 0.016 | 0.017 |
| D29 | PsV-nAb ID50 (IU50/ml) |
55/14,141 | Per 10-fold increase§ | 0.33 | (0.17, 0.65) |
0.001 | 0.002 | 0.004 |
| D57 | LV-MN50 (IU50/ml) |
47/14,064 | Per 10-fold increase | 0.51 | (0.25, 1.04) | 0.065 | 0.075 | 0.108 |
| D57 | PsV-nAb ID50 (IU50/ml) |
47/14,064 | Per 10-fold increase§ | 0.42 | (0.27, 0.65) | <0.001 | 0.003 | 0.002 |
| D29 | LV-MN50 (IU50/ml) |
55/14,141 | Per SD increase | 0.62 | (0.43, 0.91) | 0.014 | 0.016 | 0.017 |
| D29 | PsV-nAb ID50 (IU50/ml) |
55/14,141 | Per SD increase | 0.55 | (0.38, 0.79) | 0.001 | 0.002 | 0.004 |
| D57 | LV-MN50 (IU50/ml) |
47/14,064 | Per SD increase | 0.78 | (0.59, 1.02) | 0.065 | 0.075 | 0.108 |
| D57 | PsV-nAb ID50 (IU50/ml) |
47/14,064 | Per SD increase | 0.69 | (0.57, 0.83) | <0.001 | 0.003 | 0.002 |
Serological assay readouts assessed as immune correlates were first expressed in values relative to the WHO International Standard for anti–SARS-CoV-2 immunoglobulin (27): PsV-nAb titers and microneutralization assay readouts were calibrated to international units/ml (IU50/ml).
No. at-risk = estimated number in the population for analysis: baseline-negative per-protocol vaccine recipients not experiencing the COVID-19 endpoint through 6 days after D29 visit (D29 markers) or D57 visit (D57 markers); no. cases = estimated number of this cohort with an observed COVID-19 endpoint starting 7 days after D29 visit (D29 markers) or D57 visit (D57 markers).
FDR (false discovery rate)–adjusted P values and FWER (family-wise error rate)–adjusted P values were computed over the set of P values both for quantitative markers and categorical markers (low, medium, and high) using the Westfall and Young permutation method (10,000 replicates).
PsV-nAb ID50 hazard ratios per 10-fold increase were previously published [Fig. 3A and figure S17A of (10)] and are included here for comparison.
Analysis is based on baseline-negative per-protocol vaccine recipients in the D29 marker or D57 marker case-cohort set. Baseline covariates adjusted for baseline risk score, at-risk status, community of color status, and maximum failure event time 126 days after D29 visit (D29 markers) or 100 days after D57 visit (D57 markers).