COVID-19 Antibody prevalence in California

Serology study identifies 50-85-fold more people infected than the number of confirmed cases – dramatically decreasing the case fatality rate.
The population prevalence of SARS-CoV-2 antibodies in Santa Clara County implies that the infection is much more widespread than indicated by the number of confirmed cases. Population prevalence estimates can now be used to calibrate epidemic and mortality projections.
https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v1