"It was not previously known to this degree of detail and scale how viral reactivation (i.e. The findings could help researchers better understand long COVID and support the development of future diagnostic tests and treatments. Because the study only included hospitalized patients with severe COVID-19, the findings may not apply to people with mild or moderate infections. Although the study demonstrated an association between viral reactivation and severe COVID-19, it did not establish that reactivated viruses cause long COVID or long-term disability. "Although the pandemic is over, SARS-CoV-2 continues to cause infections with both acute and long-term ("long COVID") consequences," Levy wrote.