Figure 2.

Seven recurrently targeted major epitopic regions

(A) Cross competition matrix for 73 S⁺ mAbs with affinity sufficient for detection by ELISA. Blocking mAbs (columns) added at 100 μg/mL; detection antibodies (rows) at 1 μg/mL. Intensity of color shows strength of blocking, from 0 signal (complete blocking) to 70% full signal (top gradient at right of panel: orange). Hierarchical clustering of mAbs by cross competition into seven groups (plus a singleton labeled S2-3), enclosed in square boxes, with designations shown and in colors from dark blue (NTD-1) to dark red (S2-3). Green arrows on the left designate mAbs newly reported here. The lower parts of the panel show competition of blocking mAbs with soluble, human ACE2 (second gradient at right: dark red); log₁₀ (IC₅₀) (IC₅₀ unit μg/mL) in pseudovirus (614D S) neutralization assay (third gradient at right: violet); area under the curve for ELISA binding (ELISA AUC: brown); and binding (ELISA) to recombinant domains and heterologous S (green).

(B) Competition in cell-based assay for 36 mAbs with binding in ELISA format too weak for reliable blocking measurement (rows). Blocking mAbs (columns) selected from each of the seven clusters in the ELISA assay. Strength of blocking shown as intensity of orange color, as in (A).

(C) Distribution of a mAbs from two individual subjects (expressed as percent of sequence pairs recovered from that subject) into the seven principal clusters, plus a non-assigned (unknown) category (unk) and S2-3. Top row shows mAb distribution from all subjects and the bottom row shows the distribution of all other individuals minus C12 and G32.

See also Figure S2.