FIG 2.

Study 1: direct comparison between nucleocapsid-, RBD-, and spike (S1)-coated IgG ELISA plates with the cPass sVNT. (A) RBD-coated plate; (B) nucleocapsid-coated plate; (C) spike (S1)-coated plate; (D) cPass sVNT. Forty-five PCR-positive samples from patients with blood drawn more than 14 days after PCR testing were categorized by the four tests (round symbols at the left side of each chart). Of the negative delineated samples, six were shared between three tests (red dots). Twenty-three prepandemic presumed negative samples were categorized by the four tests (square symbols at the right side of each chart). Both the nucleocapsid- and RBD-coated IgG ELISA plates gave false positives.