Autoantibodies against angiotensin-converting enzyme 2 (ACE2) after COVID-19 infection or vaccination.

Autoantibodies against angiotensin-converting enzyme 2 (ACE2) are frequently reported in patients during coronavirus disease 2019 (COVID-19) with evidence for a pathogenic role in severe infection. However, little is known of the prevalence or clinical significance of ACE2 autoantibodies in late convalescence or following COVID-19 vaccination. In this study, we measured ACE2 autoantibodies in a cohort of 182 COVID-19 convalescent patients, 186 COVID-19 vaccine recipients, and 43 adolescents with post-mRNA vaccine myopericarditis using two ACE2 enzymatic immunoassays (EIAs).