Virology and Post-Infectious Mechanisms

1 Herpesvirus Reactivation and Anti-dUTPase Antibodies

  • Principal Investigator:: Mar{'}a Palomo and collaborators

  • Institution:: Multi-centre (Spain / USA)

  • Contact/URL:: https://doi.org/10.1002/jmv.70769

  • Funder:: Institutional

  • Status:: Published 2026

  • Phase:: Observational (case-control)

  • Cohort:: ME/CFS patients + healthy controls

  • Mechanism/Focus:: Measured antibodies to EBV, HHV-6, and VZV, plus anti-dUTPase IgG (a marker of active herpesvirus replication). 72.5% of ME/CFS patients simultaneously co-expressed antibodies to multiple herpesviruses versus 31% of controls. Heightened herpesvirus antibody levels clustered with moderate-to-severe fatigue.

  • Primary Outcomes:: Multi-herpesvirus co-reactivation as hallmark of post-infectious ME/CFS; anti-dUTPase IgG as fatigue-associated marker

  • Estimated Completion:: Published

  • Publication Medium:: Journal of Medical Virology

  • Document Relevance:: Ch. 7 (immune dysfunction), Ch. 9 (infection and triggers), Ch. 20 (biomarker research)

The simultaneous co-reactivation of three herpesviruses in over 70% of patients suggests systemic immune surveillance failure rather than reactivation of a single pathogen (Palomo et al. 2026). The anti-dUTPase antibody is mechanistically interesting because dUTPase is an enzyme conserved across herpesviruses that can directly activate innate immune signalling. If validated as a stratification marker, it could identify a “viral reactivation” subtype amenable to antiviral or immunomodulatory therapy.

2 Post-IM Longitudinal Cohort: Seven-Year Follow-Up

  • Principal Investigator:: Ben Z. Katz, MD

  • Institution:: Northwestern University / multi-site (USA)

  • Contact/URL:: https://doi.org/10.3389/fmed.2026.1676628

  • Funder:: NIH

  • Status:: Published 2026

  • Phase:: Observational, prospective longitudinal cohort

  • Cohort:: 4,501 college students enrolled before developing infectious mononucleosis (IM); followed for 7 years

  • Mechanism/Focus:: Uniquely prospective design: baseline data collected at least 6 weeks before IM onset. Tracks natural history from pre-infection through ME/CFS development, enabling identification of pre-existing risk factors.

  • Primary Outcomes:: ME/CFS incidence: 13% at 6 months, declining to \(\sim\) 4% at 24 months post-IM. Risk factor identification at 7-year endpoint

  • Estimated Completion:: Published

  • Publication Medium:: Frontiers in Medicine

  • Document Relevance:: Ch. 9 (infection and triggers), Ch. 23 (epidemiology), Ch. 14 Speculative Cross-Disease Connections (post-viral overlap)

This is one of the few truly prospective studies in ME/CFS, with pre-infection baseline data that enables causal inference about risk factors—a design strength shared with the DecodeME genetic study (Section Genomics and Epigenetics). The declining incidence from 13% to 4% over two years suggests spontaneous recovery in most post-IM ME/CFS cases, but the persistent 4% represents a “locked-in” subset of particular clinical and research interest (Katz et al. 2026).

3 RECOVER ME/CFS Incidence Study

  • Principal Investigator:: RECOVER Consortium

  • Institution:: NIH multi-site (USA)

  • Contact/URL:: https://doi.org/10.1007/s11606-024-09290-9

  • Funder:: NIH RECOVER Initiative

  • Status:: Published 2025

  • Phase:: Observational (adult cohort)

  • Cohort:: Large-scale RECOVER-Adult observational study

  • Mechanism/Focus:: Determined incidence and prevalence of ME/CFS following SARS-CoV-2 infection. Applies established diagnostic criteria to the largest prospective post-COVID cohort.

  • Primary Outcomes:: Confirmed that ME/CFS incidence increases following SARS-CoV-2 infection; provides population-level estimates

  • Estimated Completion:: Published

  • Publication Medium:: Journal of General Internal Medicine

  • Document Relevance:: Ch. 9 (infection and triggers), Ch. 23 (epidemiology), Ch. 14 Speculative Cross-Disease Connections

This study provides the strongest epidemiological evidence to date that SARS-CoV-2 infection increases ME/CFS incidence, confirming a pattern previously observed with EBV, Ross River virus, and Coxiella burnetii (Jason et al. 2025). The RECOVER infrastructure’s scale enables subgroup analyses by demographics, infection severity, and vaccination status that smaller cohorts cannot support.

References

Jason, Leonard A, Jasmine A Dorri, Benjamin H Natelson, Lucinda Bateman, and Suzanne D Vernon. 2025. “Incidence and Prevalence of Post-COVID-19 Myalgic Encephalomyelitis: A RECOVER-Adult Study.” Journal of General Internal Medicine. https://doi.org/10.1007/s11606-024-09290-9.
Katz, Ben Z et al. 2026. “Outcomes of ME/CFS Following Infectious Mononucleosis: Seven-Year Follow-up of a Prospective Study.” Frontiers in Medicine. https://doi.org/10.3389/fmed.2026.1676628.
Palomo, Marı́a et al. 2026. “Chronic Reactivation of Persistent Human Herpesviruses EBV, HHV-6 and VZV and Heightened Anti-dUTPase IgG Antibodies Are a Recurrent Hallmark in Post-Infectious ME/CFS and Is Associated with Fatigue.” Journal of Medical Virology. https://doi.org/10.1002/jmv.70769.