ACE2 and COVID-19: The objectives of this study were to (1) assess antibody titers in plasma samples from health systems employees, 8–10 weeks after onset of COVID-19 disease symptoms, (2) examine relationships among antibody profiles 8–10 weeks after onset of COVID-19 symptoms and demographics, pre-existing medical conditions, disease severity and duration, and symptom inventory and treatment, and (3) compare antibody profiles and ACE2 neutralization before and after a 2-dose series mRNA BNT162b2 COVID-19 vaccine.