Severe COVID-19 May Reactivate Dormant Viruses, Leading to Lasting Disability

A severe bout of COVID-19 has the potential to reawaken dormant viruses within the body, even in individuals with robust immune systems, according to recent research. The study identified Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV), and anelloviruses among the viruses that can become active again. While anelloviruses are common and have not been definitively linked to human illness, their reactivation was associated with persistent physical disability in patients experiencing long COVID.

Published in the journal Nature, the findings suggest that these reactivated viruses may contribute to the inflammation that exacerbates COVID-19 and its long-term effects. "If our findings on Anelloviridae and long COVID are validated, then it would really create a lot of urgency around better understanding these viruses and developing antivirals for them," stated study co-author Dr. Esther Melamed.

The research followed 1,154 adults hospitalized with COVID-19 of varying severity for a year, analyzing blood, nasal swabs, and lung fluid samples. The tests detected viral RNA, indicating that these latent viruses were becoming active during and after SARS-CoV-2 infection. The reactivation was widespread, affecting nearly half of the participants, and occurred even in those with healthy immune systems.

Herpes family viruses (EBV, CMV, HSV) and anelloviruses showed reactivation, with EBV and anelloviruses appearing early and CMV and HSV later. Each virus was linked to specific immune and metabolic changes and clinical complications in patients. For those who developed long COVID symptoms, such as fatigue and difficulty with daily tasks, anelloviruses were more likely to remain active after the acute infection subsided.

The study acknowledges that while the presence of viral RNA signifies gene activation, it doesn't definitively prove the creation of infectious particles. However, the researchers provided additional evidence, including the detection of EBV RNA and antibodies, along with an increase in specific immune cells where the virus resides. The study's authors also noted that the link between viral reactivation and clinical outcomes is currently correlational, not causal.

"The next step is to do prospective interventional trials to test whether antiviral medications for these reactivating viruses could help improve outcomes for people," Melamed added, suggesting this approach for both severe COVID-19 and long COVID patients.