CNN, A. K. (n.d.). Fewer than 10% in the US have antibodies to the novel coronavirus. CNN. Retrieved September 29, 2020, from https://www.cnn.com/2020/09/25/health/coronavirus-antibodies-dialysis-patients/index.html

A Brazilian city devastated by COVID-19 may have reached herd immunity. (2020, September 24). Science News. https://www.sciencenews.org/article/coronavirus-covid-19-brazil-city-manaus-herd-immunity

Commissioner, O. of the. (2020, September 23). Coronavirus (COVID-19) Update: FDA Authorizes First Point-of-Care Antibody Test for COVID-19. FDA; FDA. https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-first-point-care-antibody-test-covid-19

Wölfel, R., Corman, V.M., Guggemos, W. et al. Virological assessment of hospitalized patients with COVID-2019. Nature (2020). https://doi.org/10.1038/s41586-020-2196-x