Table 2 Covariate-adjusted hazard ratios of severe-critical COVID-19 or of moderate COVID-19 per tenfold increase or per standard deviation increase in each D29 antibody marker

From: Neutralizing antibody correlate of protection against severe-critical COVID-19 in the ENSEMBLE single-dose Ad26.COV2.S vaccine efficacy trial

 

Severe-critical COVID-19

D29 Marker

No. cases/No. at-risk

HR per 10-fold increase

p-value (2-sided)

FDR-adj p-value

FWER-adj p-value

HR per SD increase

Pt. Est.

95% CI

Pt. Est.

95% CI

nAb-ID50 (IU50/ml)

46/18,163

0.35

0.13, 0.90

0.030

0.106

0.098

0.59

0.36, 0.95

Spike IgG (BAU/ml)

46/18,163

0.67

0.32, 1.39

0.285

0.619

0.567

0.83

0.59, 1.17

RBD IgG (BAU/ml)

46/18,163

0.79

0.33, 1.85

0.583

0.633

0.793

0.90

0.63, 1.30

 

Moderate COVID-19

D29 Marker

No. cases/No. at-risk*

HR per 10-fold increase

p-value (2-sided)

FDR-adj p-value**

FWER-adj p-value**

HR per SD increase

Pt. Est.

95% CI

Pt. Est.

95% CI

nAb-ID50 (IU50/ml)

375/18,163

0.53

0.34, 0.82

0.005

0.052

0.031

0.73

0.58, 0.91

Spike IgG (BAU/ml)

375/18,163

0.67

0.45, 1.01

0.057

0.114

0.146

0.83

0.69, 1.01

RBD IgG (BAU/ml)

375/18,163

0.59

0.37, 0.93

0.025

0.073

0.076

0.80

0.65, 0.97

  1. Analyses were based on baseline SARS-CoV-2 seronegative per-protocol vaccine recipients and adjusted for baseline behavioral risk score and geographic region.
  2. *.No. at-risk = estimated number in the population for analysis, i.e. baseline negative per-protocol vaccine recipients not experiencing the designated COVID-19 endpoint or infected through 6 days post Day 29 visit; no. cases = number of this cohort with an observed designated COVID-19 endpoint (calculated via inverse probability of sampling Day 29 marker weighting).
  3. **q-value and FWER (family-wide error rate) are computed over the set of p values both for quantitative markers and categorical markers using the Westfall and Young permutation method (10000 replicates).
  4. p-values were obtained using a two-sided Wald test.
  5. Cases were counted starting 7 days post Day 29.
  6. BAU antibody binding units, CI confidence interval, FDR false discovery rate, FWER family-wise error rate, HR hazard ratio, IU international units, nAb-ID50 50% inhibitory dilution neutralizing antibody, Pt. Est. point estimate, RBD receptor binding domain, SD standard deviation.
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