Severe COVID-19 can reactivate dormant viruses hidden in the human body, with nearly half of hospitalized patients experiencing a viral reawakening, according to a major study published in Nature. Researchers found that infections disrupt internal viral ecosystems, linking specific reactivations to long COVID and severe clinical outcomes.
How COVID-19 Disrupts the Body’s Dormant Viral Ecosystem
Most people carry a baseline collection of harmless or dormant viruses that stay quiet for decades. Severe COVID-19, however, can flip the switch on those hidden pathogens. An observational analysis utilizing longitudinal data from 1,154 hospitalized patients participating in the Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study tracked biological samples across 20 U.S. hospitals. Researchers detected 11 different dormant viruses springing back to life within the first 40 days after hospital admission.
Nearly half of the patients examined experienced at least one dormant virus reactivating during their illness. The reawakened pathogens prominently featured members of the herpes family—such as Epstein-Barr virus, cytomegalovirus, and herpes simplex virus 1—which typically lurk silently in the human body until stress, illness, or hormonal shifts trigger a flare-up. Rather than acting as a single viral infection, investigators observed that SARS-CoV-2 may disrupt the body’s internal ecosystem of dormant viruses.
Challenging Assumptions About Immune Suppression and Viral Reactivation
For years, conventional medical wisdom held that chronic viral reactivation primarily targeted individuals with suppressed immune systems. This latest multiomic investigation upends that assumption. The study revealed that viral reawakening occurred frequently in individuals who had been healthy before contracting COVID-19.
“This finding suggests that COVID-19 may not always act as a single viral infection and may disrupt the body’s internal ecosystem of dormant viruses.”
Cole Maguire, lead author
Furthermore, the data challenged the mechanism linking reactivation exclusively to immune collapse. Detailed blood sample analyses indicated that Epstein-Barr virus and cytomegalovirus reactivated in direct response to systemic inflammation itself. This revelation reframes long-term post-viral syndromes as inflammatory disorders just as much as immunological ones, opening new avenues for understanding why recovery remains elusive for millions.
Anelloviridae, Inflammation, and the Long COVID Connection
Among the eleven reactivated agents, the Anelloviridae family emerged as a critical clinical signal. Anelloviridae is a poorly understood group of viruses that typically remain latent in about 90 percent of the human population. Researchers discovered that the reactivation of these persistent viruses was strongly tied to long-term physical disability and long COVID, marking it as one of the most significant discoveries in the dataset.
Patients whose dormant infections resurfaced also faced worse immediate prognoses. They experienced more severe illness, spent extended periods in the hospital, developed serious complications, and faced higher mortality rates.
Translating Biomarkers Into Future Diagnostic and Treatment Strategies
While the observational data stops short of proving that dormant viral reactivation directly causes long COVID, it delivers robust immunological, transcriptomic, and metabolomic signatures. These signatures provide medical science with concrete targets to prognosticate and treat acute illness and chronic post-viral conditions alike.
Diagnostic tests already exist for several of the chronic viruses examined in the cohort, and existing antiviral drugs can target specific herpes family members. Researchers emphasize that identifying viral activity early could eventually allow clinicians to flag patients at risk of prolonged disability before it fully sets in, shifting therapeutic focus toward targeted anti-inflammatory interventions and personalized treatment strategies.
