Low Prevalence of Interferon α Autoantibodies in People Experiencing Symptoms of Post–Coronavirus Disease 2019 (COVID-19) Conditions, or Long COVID

We studied the blood of LIINC volunteers for aberrant antibodies specific to self-proteins called interferons. These antibodies are sometimes detrimental to the immune response as interferon proteins help ramp up the immune response during infections. The presence of such antibodies is thought to be a potential driver of severe COVID-19. However, in the context of Long COVID, we found that antibodies specific to interferon were not present in the vast majority of LIINC participants, indicating that they are an unlikely driver of long COVID symptoms among people who have had COVID-19.