COVID-19 awakens dormant viruses — and one is linked to long COVID

A new study published in Nature reveals that the COVID-19 virus can reactivate dormant viruses in hospitalized patients, potentially contributing to long-term health conditions. Researchers from Boston Children's Hospital and 14 other institutions across the United States analyzed blood samples from 1,154 patients over a year, identifying 11 reactivated viruses within the first 40 days of hospital admission.

The most frequently detected reactivated viruses were Epstein-Barr, herpes simplex 1, cytomegalovirus, and Anelloviridae. Among these, the reactivation of Anelloviridae, a family of viruses that typically remains latent in about 90% of the population, showed a strong association with long-term physical disability and "long COVID."

This finding suggests that COVID-19 may play a role in autoimmune diseases and other long-lasting health conditions. The study's lead, Ofer Levy, MD, PhD, emphasized the importance of understanding the molecular and viral associations with long COVID to improve diagnostics and treatments. The research also uncovered an unexpected mechanism in which Epstein-Barr and cytomegalovirus became active in response to inflammation rather than due to immunosuppression.

This challenges the prevailing idea that chronic viral reactivation occurs mainly because of immunosuppression.