Almost 10 weeks into the pandemic, COVID-19 is continuing to surprise and baffle health experts.
In fact, experts’ picture of exactly how COVID-19 might play out in the body is now quite different to what was thought as little as a few weeks ago, with some experts saying it could be better described as three different diseases.
We have known for a while that the mild to moderate form of the disease — a flu-like illness with fever, muscle aches and respiratory symptoms, or often no symptoms at all — is almost like “child’s play” compared to the major damage to organs like the the lungs, heart, brain, and kidneys seen when COVID-19 becomes severe.
Umesh Gidwani, head of cardiac intensive care at New York’s Mount Sinai Hospital, says that trying to treat the severe form of the disease is like facing a terrifying fire, burning out of control.
“The patients we take care of [in intensive care] are those in whom the fire has already destroyed the house. But there continues to be embers and small fires. I can’t enter the house because it’s too hot and things are falling on me,” he says.
“[Severe disease] is almost a completely different animal [compared] to someone who is recovering at home with some chicken soup and paracetamol”.
And now it seems there is evidence of a third variation in illness that can occur following exposure to the virus — a mysterious new disease given the name paediatric multisystem inflammatory syndrome, with an entirely different set of symptoms again.
The syndrome seems to only affect children, unlike both mild and severe COVID-19, which mostly affect adults. However the link between the inflammatory syndrome and the virus that causes COVID-19 is not yet 100 per cent confirmed.
The bottom line, says Dr Gidwani, is what we have been calling a single disease — COVID-19 — is really looking more like three separate diseases.
He and others draw this conclusion based on how the virus affects the immune system.
“The key disaster is the extent and severity of the immune response,” he says.
It is now clear the symptoms experienced by people with severe COVID-19 are largely caused by the body’s disordered immune response to the virus rather than the virus itself, Dr Gidwani says.
In fact, the disordered immune response in severe COVID-19 is the disease; they are one and the same thing.
Image Credit: Umesh Gidwani
News This Week
Can introducing peanuts early prevent allergies? Real-world data confirms it helps
New evidence from a large U.S. primary care network shows that early peanut introduction, endorsed in 2015 and 2017 guidelines, was followed by a marked decline in clinician-diagnosed peanut and overall food allergies among [...]
Nanoparticle blueprints reveal path to smarter medicines
Lipid nanoparticles (LNPs) are the delivery vehicles of modern medicine, carrying cancer drugs, gene therapies and vaccines into cells. Until recently, many scientists assumed that all LNPs followed more or less the same blueprint, [...]
How nanomedicine and AI are teaming up to tackle neurodegenerative diseases
When I first realized the scale of the challenge posed by neurodegenerative diseases, such as Alzheimer's, Parkinson's disease and amyotrophic lateral sclerosis (ALS), I felt simultaneously humbled and motivated. These disorders are not caused [...]
Self-Organizing Light Could Transform Computing and Communications
USC engineers have demonstrated a new kind of optical device that lets light organize its own route using the principles of thermodynamics. Instead of relying on switches or digital control, the light finds its own [...]
Groundbreaking New Way of Measuring Blood Pressure Could Save Thousands of Lives
A new method that improves the accuracy of interpreting blood pressure measurements taken at the ankle could be vital for individuals who are unable to have their blood pressure measured on the arm. A newly developed [...]
Scientist tackles key roadblock for AI in drug discovery
The drug development pipeline is a costly and lengthy process. Identifying high-quality "hit" compounds—those with high potency, selectivity, and favorable metabolic properties—at the earliest stages is important for reducing cost and accelerating the path [...]
Nanoplastics with environmental coatings can sneak past the skin’s defenses
Plastic is ubiquitous in the modern world, and it's notorious for taking a long time to completely break down in the environment - if it ever does. But even without breaking down completely, plastic [...]
Chernobyl scientists discover black fungus feeding on deadly radiation
It looks pretty sinister, but it might actually be incredibly helpful When reactor number four in Chernobyl exploded, it triggered the worst nuclear disaster in history, one which the surrounding area still has not [...]
Long COVID Is Taking A Silent Toll On Mental Health, Here’s What Experts Say
Months after recovering from COVID-19, many people continue to feel unwell. They speak of exhaustion that doesn’t fade, difficulty breathing, or an unsettling mental haze. What’s becoming increasingly clear is that recovery from the [...]
Study Delivers Cancer Drugs Directly to the Tumor Nucleus
A new peptide-based nanotube treatment sneaks chemo into drug-resistant cancer cells, providing a unique workaround to one of oncology’s toughest hurdles. CiQUS researchers have developed a novel molecular strategy that allows a chemotherapy drug to [...]
Scientists Begin $14.2 Million Project To Decode the Body’s “Hidden Sixth Sense”
An NIH-supported initiative seeks to unravel how the nervous system tracks and regulates the body’s internal organs. How does your brain recognize when it’s time to take a breath, when your blood pressure has [...]
Scientists Discover a New Form of Ice That Shouldn’t Exist
Researchers at the European XFEL and DESY are investigating unusual forms of ice that can exist at room temperature when subjected to extreme pressure. Ice comes in many forms, even when made of nothing but water [...]
Nobel-winning, tiny ‘sponge crystals’ with an astonishing amount of inner space
The 2025 Nobel Prize in chemistry was awarded to Richard Robson, Susumu Kitagawa and Omar Yaghi on Oct. 8, 2025, for the development of metal-organic frameworks, or MOFs, which are tunable crystal structures with extremely [...]
Harnessing Green-Synthesized Nanoparticles for Water Purification
A new review reveals how plant- and microbe-derived nanoparticles can power next-gen water disinfection, delivering cleaner, safer water without the environmental cost of traditional treatments. A recent review published in Nanomaterials highlights the potential of green-synthesized nanomaterials (GSNMs) in [...]
Brainstem damage found to be behind long-lasting effects of severe Covid-19
Damage to the brainstem - the brain's 'control center' - is behind long-lasting physical and psychiatric effects of severe Covid-19 infection, a study suggests. Using ultra-high-resolution scanners that can see the living brain in [...]
CT scan changes over one year predict outcomes in fibrotic lung disease
Researchers at National Jewish Health have shown that subtle increases in lung scarring, detected by an artificial intelligence-based tool on CT scans taken one year apart, are associated with disease progression and survival in [...]
