Table 1.
D35 antibody marker SARS-CoV-2 seroresponse rates and geometric means in the U.S. cohort by COVID-19 outcome status
| D35 Marker | COVID-19 Casesa | Non-Cases in Immunogenicity Subcohortb | Comparison | |||||
|---|---|---|---|---|---|---|---|---|
| N | Proportion with Antibody Responsec (95% CI) | Geometric Mean (GM) (95% CI) | N | Proportion with Antibody Responsec (95% CI) | Geometric Mean (GM) (95 % CI) | Response Rate Difference (Non-Cases–Cases) | Ratio of GM (Non-Cases/Cases) | |
| Anti Spike IgG (BAU/ml) | 12 | 91.7% (52.5%, 99.1%) | 528 (184, 1513) | 639 | 99.6% (99.2%, 99.8%) | 1552 (1407, 1713) | 8.0% (0.5%, 47.2%) | 2.9 (1.0, 8.3) |
| Anti RBD IgG (BAU/ml) | 12 | 91.7% (52.5%, 99.1%) | 722 (270, 1931) | 639 | 98.5% (97.1%, 99.2%) | 2123 (1904, 2369) | 6.8% (−0.7%, 46%) | 2.9 (1.1, 7.7) |
| Pseudovirus-nAb ID50 (IU50/ml) | 12 | 83.3% (47.6%, 96.5%) | 135 (35, 519) | 639 | 98.8% (97.5%, 99.4%) | 461 (404, 526) | 15.4% (2.2%, 51.2%) | 3.4 (0.9, 12.5) |
aCases are baseline SARS-CoV-2 seronegative per-protocol vaccine recipients with the primary COVID-19 endpoint (symptomatic RT-PCR-confirmed COVID-19) starting 7 days post D35 visit through to the data cut (April 19, 2021).
bNon-cases are baseline negative per-protocol vaccine recipients sampled into the immunogenicity subcohort with no evidence of SARS-CoV-2 infection (i.e., never tested RT-PCR positive) up to the end of the correlates study period (the data cut-off date April 19, 2021).
cAntibody response defined by IgG concentration above the assay positivity cut-off (10.8424 BAU/ml) or by detectable ID50 > limit of detection (LOD) = 2.612 IU50/ml.
Analysis based on baseline SARS-CoV-2 negative per-protocol vaccine recipients in the case-cohort set. Median (interquartile range) days from vaccination to D35 was 38 (6).