Table 3 SARS-CoV-2 seroprevalence in hospitalized patients with COVID-19, mildly symptomatic individuals, and healthy blood donors.

CohortELISA NELISA tri-SS-FlowLIPS S1 + NAntibody prevalence
Pre-pandemic
individuals (specificity)
23/491 (95%)5/100 (95%)0/134 (100%)3/280 (99%)
Hospitalized patients
(seroprevalence)
33/51 (65%)35/51 (69%)21/29 (72%)35/51 (69%)69% (65–72%)
Mildly symptomatic
individuals
56/209 (27%)75/209 (36%)73/209 (35%)68/209 (32%)32% (27–36%)
Healthy blood donors0/2002/166/2000/2003%