IMAGE DESCRIPTION: An image of a hospital scanner with a circular image of a light box saying 'Post Covid' i.e. Long Covid. The title reads: Science Alert: Full-Body Scans Reveal Long-Term Immune Effects. The ME Association Logo (bottom right)

Science Alert: Long Covid: Full-Body Scans Reveal Long-Term Immune Effects

Long Covid is a brutal illness without a known mechanism or cure. Far from being psychosomatic in nature, a new study adds weight to the idea that this misunderstood disease is very much biological.

By Carly Cassella


The lingering toll the SARS-CoV-2 virus exacts on the immune system is widespread and hiding in plain sight, argue researchers at the University of California, San Francisco, CellSight Technologies, and Kaiser Permanente South San Francisco Medical Center.

When 24 patients who had recovered from COVID-19 had their whole bodies scanned by a PET (positron emission tomography) imaging test, their insides lit up like Christmas trees.

A radioactive drug called a tracer revealed abnormal T cell activity in the brain stem, spinal cord, bone marrow, nose, throat, some lymph nodes, heart and lung tissue, and the wall of the gut, compared to whole-body scans from before the pandemic.

CFS/ME shares many of the same symptoms as Long Covid, and some scientists suspect they may be one and the same. Brain scans have found that long COVID changes to the brain parallel the effects of CFS/ME, and recently, a landmark study confirmed that CFS/ME is “unambiguously biological” with multiple organ systems affected.

Today, Long Covid is increasingly recognized as having neurological underpinnings, and the recent discovery of T cell abnormalities in the spinal cord and brain stem suggest that these overactive immune cells are being ‘trafficked' to tissues of the central nervous system.

MEA Comment

Although there is a lot of clinical/symptom and pathological overlap between Long Covid and ME/CFS one important difference may be that in some people with Long Covid there is evidence of persisting viral infection with Covid-19.

This new research from America, using a special type of neuroimaging called PET scanning, adds further support to the presence of persisting viral infection and immune system activation in Long Covid.

Dr Charles Shepherd,
Trustee and
Hon. Medical Adviser
to the ME Association.
Member of the 2018-2021 NICE Guideline Committee.
Member of the 2002 Independent Working Group on ME/CFS.

Dr Charles Shepherd

Further Information

Science Translational Medicine: Tissue-based T cell activation and viral RNA persist for up to 2 years after SARS-CoV-2 infection (abstract)

Stat News: ‘Visionary’ study finds inflammation, evidence of Covid virus years after infection  | 3rd July 2024

Science Media Centre: Expert reaction to study looking at T cell activation and viral RNA persistence in Long Covid | 3rd July 2024

Medical Xpress: Long COVID uncharacteristic immune cell activity and SARS-CoV-2 RNA found in the gut two years after infection | 8th July 2024

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