Table 2. SARS-CoV-2 IgG Binding and Neutralizing Antibody Assays.
IgG serum antibody responses to wildtype (S-2P-WA-1) and IU50 neutralizing antibody titers to pseudovirus D614G and bridged to international standards and reported as Binding Antibody Units/mL via a 4-plex ECLIA assay and international units ID50/mL (IU50/mL), respectively. Results are reported by Primary immunization EUA Vaccine, Booster vaccine and Timepoint.
| Group | 1 | 3 | 4 | 6 | 7 | 9 | |||
|---|---|---|---|---|---|---|---|---|---|
| Primary EUA Immunization Vaccine | Janssen Ad26.COV2-S 5×1010 vp | Pfizer/BioNTech BNT162b2 30-mcg | Janssen Ad26.COV2-S 5×1010 vp | Pfizer/BioNTech BNT162b2 30-mcg | Janssen Ad26.COV2-S 5×1010 vp | Pfizer/BioNTech BNT162b2 30-mcg | |||
| Booster | Moderna mRNA-1273 100-mcg | Janssen Ad26.COV2-S 5×1010 vp | Pfizer/BioNTech BNT162b2 30-mcg | ||||||
| IgG Serum Binding Antibody (Binding Antibody Units/mL) | |||||||||
| N at Study Day 15 | 51 | 50 | 50 | 50 | 50 | 48 | |||
| Day 1 GMT* (95% CI)† | 57.1 (44.6–73.2) | 859.2 (668.3–1104.6) | 356.6 (262.5–484.5) | 71.3 (47.9–106.2) | 638.8 (513.7–794.2) | 320.6 (250.7–410.1) | 75.1 (54.8–102.8) | 534.4 (444.8–642.0) | 223.5 (177.4–281.7) |
| Day 15 GMT (95% CI) | 3203.1 (2499.5–4104.9) | 6799.8 (5771.8–8010.9) | 6155.0 (4895.4–7738.7) | 326.0 (235.8–450.7) | 3029.4 (2433.2–3771.7) | 1904.7 (1497.8–2422.2) | 2549.5 (2038.1–3189.3) | 5195.6 (4433.1–6089.3) | 3409.1 (2760.6–4209.8) |
| Day 29 GMT (95% CI) | 2803.1 (2263.3–3471.7) | 5917.4 (5070.4–6905.9) | 5170.2 (4156.9–6430.6) | 368.6 (290.8–467.4) | 4560.1 (3544.2–5867.2) | 2599.6 (2085.9–3239.9) | In process | In process | In process |
| Percentage with two-fold rise at Day 15 (95% CI) | 100.0% (93.2–100.0%) | 96.0% (86.3–99.5%) | 98.0% (89.4–99.9%) | 86.0% (73.3–94.2%) | 83.7% (70.3–92.7%) | 92.0% (80.8–97.8%) | 98.0% (89.4–99.9%) | 100.0% (92.6–100.0%) | 100.0% (92.6–100.0%) |
| Geometric mean fold rise (95% CI) | 56.1 (40.7–77.2) | 7.9 (6.2–10.1) | 17.3 (13.3–22.4) | 4.6 (3.7–5.7) | 4.7 (3.6–6.2) | 6.2 (4.7–8.1) | 32.8 (24.6–43.8) | 9.7 (8.0–11.8) | 14.9 (11.8–18.9) |
| Neutralizing Antibody Titer (International Unit (IU)/mL) | |||||||||
| D614G ‡ | |||||||||
| Day 1 GMT (95% CI) | 8.9 (6.2–12.8) | 88.7 (67.7–115.9) | 24.8 (18.0–34.2) | 7.6 (4.9–11.8) | 61.7 (45.0–84.6) | 18.6 (13.4–25.7) | 9.4 (6.4–13.6) | 57.6 (45.0–73.7) | 21.4 (15.3–30.0) |
| Day 15 GMT (95% CI) | 676.1 (517.5–883.3) | 901.8 (727.5–1117.8) | 785.8 (596.4–1035.2) | 31.42 (22.3–44.3) | 382.1 (290.5–502.5) | 216.4 (157.8–296.9) | 341.3 (239.6–486.3) | 677.9 (559.4–821.3) | 446.7 (340.3–586.3) |
| Day 29 GMT (95% CI) | 431.7 (322.6–577.6) | 700.0 (568.6–861.8) | 495.7 (370.4–663.4) | In process | In process | In process | In process | In process | In process |
| Percentage with four-fold rise at Day 15 (95% CI) | 100.0% (93.2%−100.0%) | 86.0% (73.3%−94.2%) | 100.0% (92.9%−100.0%) | 50.0% (35.5–64.5%) | 61.2% (46.2–74.8%) | 82.0% (68.6–91.4%) | 98.0% (89.0–99.9%) | 93.8% (82.8–98.7%) | 97.9% (88.9–99.9%) |
| Day 15 geometric mean fold rise (95% CI) | 75.9 (55.0–104.8) | 10.2 (8.0–12.8) | 31.7 (23.8–42.2) | 4.2 (3.0–5.8) | 6.2 (4.5–8.5) | 12.5 (8.7–17.9) | 35.1 (23.9–51.6) | 11.5 (9.0–14.8) | 20.0 (14.6–27.4) |
*
GMT- Geometric mean titers
†
CI- Confidence Intervals
‡
Sample size matches binding antibody