Immune Systems Advisor

Long COVID vs ME/CFS: Understanding Post-Viral Syndromes Long COVID (post-acute sequelae of SARS-CoV-2 infection, PASC) and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are two post-viral syndromes that share overlapping symptoms such as fatigue, brain fog, and post-exertional malaise. However, recent studies highlight unique mechanistic and clinical differences, particularly in inflammation, endothelial injury, and energy metabolism. This article provides an evidence-based comparison, with links to related topics on spike protein persistence, endothelial dysfunction, mitochondrial dysfunction & NAD⁺, and nutraceutical interventions. Epidemiology: Who Gets Long COVID vs ME/CFS? Key Points: Long COVID affects ~10–30% of COVID survivors (WHO, 2023) ME/CFS affects ~0.2–0.5% of the population (Jason et al., 2021) Long COVID can affect all age groups, peak 40–60; ME/CFS peaks 30–50 Both show female predominance; stronger in ME/CFS Related:   Long COVID overview Clinic...

The study titled, Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination , was published in Nutrition (2025): Background Prolonged symptoms have been reported following both COVID-19 infection and vaccination, with some cases leading to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Of 80 patients presenting to our hospital with postvaccination syndrome, 28 met the diagnostic criteria for ME/CFS. We conducted a retrospective study on these 28 patients. Methods We measured serum 25-hydroxyvitamin D levels in 28 patients who developed ME/CFS after COVID-19 vaccination between August 2022 and February 2024. Vitamin D replacement therapy included dietary counseling, sun exposure recommendations, and oral vitamin D supplementation. We evaluated changes in blood vitamin D levels and symptom improvement. Results At initial visit, 27 of 28 patients diagnosed with ME/CFS had insufficient or deficient...

Return guest Dr. Paul Saladino is a board-certified psychiatrist and also board certified in nutrition. He wrote "The Carnivore Code," which just came out in an updated second edition. In this interview, he discusses the impact metabolic health has on COVID-19 outcomes. He's done a magnificent job explaining the science that supports the natural lifestyle strategies that optimize our immune systems to defeat not only COVID-19, but also most other infectious agents. "The psychiatry was a jump-off point for thinking about how immune function and metabolic health affects mental health," he says. "I quickly realized that everything in the body was connected and I couldn't just focus on the brain without focusing on the rest of the body, and that has led us to where we are today. I think that as we are faced with coronavirus, it's a reminder of the metabolic health and how critical that is. I think so much of the...

Abstract Persistent symptoms following SARS‑CoV‑2 infection, collectively termed Long COVID or post‑acute sequelae of COVID‑19 (PASC), remain a significant clinical challenge. One proposed biological mechanism involves prolonged presence of SARS‑CoV‑2 spike protein or viral RNA fragments post‑infection. Additional questions concern spike protein dynamics after COVID‑19 vaccination. This review synthesizes current peer‑reviewed evidence on spike protein detection after natural infection and vaccination, clarifying clinical context, limitations, and implications. Data indicate that SARS‑CoV‑2 spike protein and/or fragments can be detected in circulation or tissues up to a year or longer post‑infection, especially in PASC cohorts, whereas vaccine‑derived spike is typically transient and associated with rapid immune clearance. Mechanistic and clinical significance remains an area of ongoing research. Keywords: SARS‑CoV‑2, spike protein, long COVID, PASC, post‑vaccination, antigen persiste...

More than four years following the emergence of COVID-19, a subset of individuals experience persistent, multisystem symptoms extending beyond three months post-infection or post-exposure to mRNA-based COVID-19 vaccines.  This condition, historically termed "Long COVID," has recently been redefined by some researchers as "Post-Spike Syndrome" (PSS) or "SPIKEOPATHY," emphasizing the pathogenic role of the SARS-CoV-2 Spike protein derived from both viral infection and mRNA vaccination.  This article summarizes the most recent scientific findings and clinical advances to help patients and healthcare providers better understand and manage this complex condition. Update: Long COVID in 2026 : Integrative Biological Insights and Therapeutic Considerations Latest Research Insights on Long COVID Immune System Markers and Genetic Risk Factors A recent clinical study led by Cardiff Metropolitan University and Cwm Taf Morgannwg University Health Board identified eleva...