Table 1.
BD1, BD29, and Fold-Rise BA.1 strain neutralizing antibody (nAb) and Spike IgG-BA
| Omicron Casesa | Non-Casesb | Comparison | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Statusc | Marker | Measurement | Nd | Response Ratee (95% CI) | GMC or GMT (AU/ml) (95% CI) | Nd | Response Rate (95% CI)e | GMC or GMT (AU/ml) (95% CI) | Response Rate Difference (Omicron Cases-Non-Cases) (95% CI) | Ratio of GM (Omicron Cases/Non-Cases) (95% CI) |
| Naive | BA.1 Strain nAbs | BD1 | 79 | 84.1% (69.1%, 92.6%) | 11.4 (9.1, 14.3) | 84 | 93.0% (84.6%, 96.9%) | 14.6 (12.1, 17.6) | -0.09 (-0.24, 0.03) | 0.78 (0.58, 1.05) |
| Naive | Spike IgG-BA.1 Strain bAbs | BD1 | 79 | 98.3% (88.3%, 99.8%) | 3621 (2621, 5004) | 84 | 100% (100%, 100%) | 3353 (2646, 4248) | -0.017 (-0.12, -0.002) | 1.08 (0.72, 1.61) |
| Naive | BA.1 Strain nAbs | BD29 | 79 | 100% (100%, 100%) | 259 (194, 347) | 84 | 100% (100%, 100%) | 491 (341, 706) | 0 (0, 0) | 0.53 (0.33, 0.84) |
| Naive | Spike IgG-BA.1 Strain bAbs | BD29 | 79 | 100% (100%, 100%) | 113,143 (87,402, 146,464) | 84 | 100% (100%, 0.0%) | 170,731 (137,772, 211,574) | 0 (0, 0) | 0.66 (0.47, 0.93) |
| Naive | BA.1 Strain nAbs | Fold-Rise (BD29/BD1) | 79 | - | 23 (17.5, 29.4) | 84 | - | 34 (24.6, 46.1) | - | 0.67 (0.45, 1.01) |
| Naive | Spike IgG-BA.1 Strain bAbs | Fold-Rise (BD29/BD1) | 79 | - | 31.2 (24.8, 39.3) | 84 | - | 50.9 (42.0, 61.6) | - | 0.61 (0.45, 0.83) |
| Non-Naive | BA.1 Strain nAbs | BD1 | 32 | 91.4% (74.9%, 97.4%) | 28.3 (17.0, 47.1) | 23 | 96.2% (74.0%, 99.6%) | 19.1 (11.7, 31.1) | -0.048 (-0.22, 0.18) | 1.48 (0.73, 3.00) |
| Non-Naive | Spike IgG-BA.1 Strain bAbs | BD1 | 32 | 100% (100%, 100%) | 7513 (4658, 12117) | 23 | 100% (100%, 100%) | 4406 (2907, 6678) | 0 (0, 0) | 1.71 (0.90, 3.21) |
| Non-Naive | BA.1 Strain nAbs | BD29 | 32 | 100% (100%, 100%) | 346 (231, 517) | 23 | 100% (100%, 100%) | 572 (345, 949) | 0 (0, 0) | 0.60 (0.32, 1.15) |
| Non-Naive | Spike IgG-BA.1 Strain bAbs | BD29 | 32 | 100% (100%, 100%) | 90,534 (63,315, 129,453) | 23 | 100% (100%, 100%) | 148,330 (96,969, 226,897) | 0 (0, 0) | 0.61 (0.35, 1.06) |
| Non-Naive | BA.1 Strain nAbs | Fold-Rise (BD29/BD1) | 32 | - | 12.2 (7.6, 19.7) | 23 | - | 30.0 (18.3, 49.1) | - | 0.41 (0.20, 0.81) |
| Non-Naive | Spike IgG-BA.1 Strain bAbs | Fold-Rise (BD29/BD1) | 32 | - | 12.0 (7.2, 20.0) | 23 | - | 33.7 (22.6, 50.2) | - | 0.36 (0.19, 0.68) |
1 strain binding antibody (bAb) response rates and geometric means by Omicron COVID-19 case vs. non-case status and by SARS-CoV-2 naive vs. non-naive status in the per-protocol boosted cohort, pooled across the original-vaccine and crossover-vaccine arms.
AU/ml arbitrary units/ml, CI confidence interval, GMC geometric mean concentration, GMT geometric mean titer.
aOmicron case = COVID-19 Omicron BA.1 endpoint that occurred in the interval [≥7 days post BD29 AND ≥December 1, 2021 to April 5, 2022 data cutoff].
bNon-case = No acquirement of COVID-19 (of any strain) in the interval [BD1, April 5, 2022 data cutoff].
cNaive = No evidence of SARS-CoV-2 infection from enrollment through to BD1; Non-naive = Any evidence of SARS-CoV-2 infection in the interval [≥14 days after the original two-dose series, BD1].
dN is the number of cases sampled into the subcohort within baseline covariate strata.
eDefinition of “responder” for a marker measured on a given time-point: positive (quantifiable) response defined as BA.1 strain nAb titer on that time-point ≥8 AU/ml; positive response defined as Spike IgG-BA.1 strain bAb concentration on that time-point ≥102 AU/ml.