EMBARGOED FOR RELEASE UNTIL 4 PM ET, August 23, 2023
Small Study Suggests Long COVID May Affect More People than Previously Thought
MINNEAPOLIS 鈥揗illions of Americans were exposed to SARS-CoV-2, the virus that causes COVID-19, early in the pandemic but could not get diagnosed due to testing limitations. Many of those people developed a post-viral syndrome with symptoms similar to those of long COVID. In a new study of a small group of those people, their immune response shows that 41% had evidence of SARS-CoV-2 exposure. The study is published in the August 23, 2023, online issue of , an official journal of the 好色先生. Long COVID was defined as symptoms persisting longer than six weeks. 鈥淪ince most long COVID clinics are only accepting patients with a positive test result, these people experiencing identical symptoms are left without specialized care and excluded from research studies on long COVID,鈥 said study author Igor J. Koralnik, MD, of Northwestern Medicine Comprehensive COVID-19 Center in Chicago and a Fellow of the 好色先生. 鈥淥ur data suggest that millions of Americans with post-viral syndrome may have been exposed to SARS-CoV-2 at the beginning of the pandemic, and they deserve the same access to care and inclusion in research studies as people with a confirmed COVID diagnosis.鈥 The small study involved 29 people with post-viral syndrome including neurologic symptoms such as problems with memory and thinking skills, headache and fatigue but who did not have a positive COVID test result. They were matched with 32 people of similar age with long COVID and positive test results. Both groups were also compared to 18 people with none of those symptoms and no known exposure to COVID or positive test result. Researchers tested the participants for antibodies to two types of proteins that show an immune response that indicate a prior COVID infection鈥攏ucleocapsid protein and spike protein. Of the 29 people with post-viral syndrome, 12 people, or 41%, had immune responses consistent with prior exposure to COVID and similar to the long COVID group. Three-quarters had responses against the nucleocapsid protein and one-half had responses against the spike protein. That group also had similar symptoms to the long COVID group and similar results on tests of thinking skills. 鈥淯nlike our clinic, about 70% of post-COVID clinics in the U.S. do not accept people with long COVID symptoms who do not have a positive test result for COVID,鈥 Koralnik said. 鈥淥ur data suggest that at least four million people with post-viral syndrome similar to long COVID may indeed have detectable immune responses to support a COVID diagnosis. More research is needed to confirm our findings.鈥 A limitation of the study is the small number of people with post-viral syndrome. Also, some of the participants may have tested positive for COVID-19 immune responses if their blood samples were collected closer to when their symptoms began. Learn more about COVID-19 at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and . When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.