One of the study’s surprising findings was that viral reactivation occurred even in people with otherwise healthy immune systems. (Express Archive)A severe COVID-19 infection may do more than attack the body on its own. It can also awaken dormant viruses that have remained inactive for years, potentially worsening illness and increasing the risk of long COVID, according to a study published in Nature. Nearly half showed evidence that common viruses lying dormant in their bodies had become active again during their illness. The study also found reactivation of anelloviruses, a group of viruses that are widespread in humans and are generally considered harmless.