010203040100mAbconcentration(ng/mL)O.D.4 5 0nmb% mAb binding inhibitionmAbconcentration(ng/mL)O.D.450nmSerum or plasma dilutionCOV2-2130 COV2-2196Individual 1 plasma Individual 2 serum Individual 3 plasmaIndividual 4 plasma Individual 5 serum (healthy)01020304010010 -2 10 -1 10 -2 10 -10255075100mAbconcentration(ng/mL)O.D.4 5 0nma% human ACE2 inhibitionSerum or plasma dilution10 -3 10 -2 10 -1Extended Data Fig. 4 | Competition-binding analysis of serum or plasma
antibodies with human ACE2 and monoclonal antibodies. a, Inhibition of
human ACE2 binding to S2Pecto by serum or plasma of four SARS-CoV-2 immune
individuals or one non-immune control individual in an ELISA using SARS-
C oV-2 S 2 Pecto. Monoclonal antibodies were isolated from individuals 3 and 4 as
described previously^5. Data are mean ± s.d. of triplicates of one experiment.
Dotted line indicates full inhibition (100%) of human ACE2 by 500 ng ml−1 of
monoclonal antibody COV2-2196 or COV2-2130 that were used as controls for
full human ACE2 inhibition. b, Inhibition of monoclonal antibody COV2-2130
(left) or COV2-2196 (right) binding to S2Pecto by serum or plasma of four
SARS-CoV-2 immune individual or one non-immune control individual in an
ELISA using SARS-CoV-2 S2Pecto. Data are mean ± s.d. of triplicates, and are
representative of two experiments. Dotted line indicates the percentage of
self-competition of monoclonal antibodies COV2-2196 and-2130 on the
SARS-CoV-2 S2Pecto antigen.