Table 4.
Inhibition (IC50) of ACE-2 binding to SARS-CoV-2 spike protein variants by trimeric nanobodies measured by electrochemiluminescence in MULTISPOT plates (Meso Scale Diagnostics).
| variant | A8 | C1 | C5 | H6 | B5-5 |
|---|---|---|---|---|---|
| IC50 (nM) | |||||
| ancestral | 0.89 | 1.64 | 0.98 | 1.91 | >100 |
| Alpha | 0.72 | 1.62 | 0.87 | 1.74 | >100 |
| Beta | 0.8 | 1.84 | NI | 1.59 | >100 |
| Delta | 0.67 | 1.94 | 0.97 | 2.08 | >100 |
| Omicron BA.1 | 10.87 | 3.26 | NI | 1.8 | >100 |
| Omicron BA.2.12.1 | NI | >100 | NI | 3.39 | ND |
| Omicron BA.2 + L452M | NI | >100 | NI | 4.28 | ND |
| Omicron BA.2 + L452R | NI | >100 | NI | 3.3 | ND |
| Omicron BA.2 | NI | >100 | NI | 4.18 | ND |
| Omicron BA.3 | 22.26 | 0.89 | NI | 2.39 | ND |
| Omicron BA.4 | >100 | >100 | NI | 0.96 | ND |
| Omicron BA.5 | NI | >100 | NI | 1.09 | ND |
ND, Not Determined; NI, non-inhibitory.