SARS-CoV-2 Virus a.k.a. The “Coronavirus” (Image via wikipedia.com)
Staff Writer: Maya Arruda
Email: marruda7@umassd.edu
Post-pandemic, we or someone we know have all gotten COVID. Typically, getting COVID entails being sick for a miserable two weeks, chugging cough syrup like it’s water just to alleviate some of the symptoms.
While most individuals infected with SARS-CoV-2, the virus behind COVID-19, receive cold/flu-like symptoms and are perfectly fine within two weeks or so, this is not the case with everyone. Some COVID cases require hospitalization, usually for lower respiratory tract symptoms (I.e., lung complications like pneumonia and even ARDS lung failure) or for cytokine storm complications, both of which can be deadly.
Even in cases that do not require hospitalization, there can be long-term side effects of SARS-CoV-2 infection.
The CDC defines Long COVID as a series of long-term signs, symptoms, and conditions caused by acute COVID-19 infection. In layman’s terms, long COVID is anything medically wrong caused by COVID that lingers after the two-week flu-like phase.
Just to name a few, Long COVID symptoms can include:
- Fever
- Fatigue
- Brain Fog
- Joint & Muscle Pain
- Heart Palpitations
- Depression & Anxiety
- Dizziness
- Changes in Smell and/or Taste
- Nerve Damage
- Autoimmune Conditions
- Malaise
- Post-Intensive Care Syndrome
Due to how permanently damaging it can be, as of July 2021, Long Covid is considered a disability under the Americans with Disabilities Act.
The autoimmune conditions usually derive from an increased, prolonged inflammatory immune response against an antigen, in this case, the SARS-CoV-2 virus. Cytokine storms, exhibited in severe COVID cases, demonstrate how a COVID-19 infection can negatively impact the immune system and entice it to seriously damage the patient. The other Long COVID symptoms, like fever and fatigue, match common symptoms of almost any infectious disease.
But how does SARS-CoV-2, a respiratory virus, end up causing all these neurological symptoms in Long COVID cases?
A recent paper in Nature published in February 2024 by Greene et al. attempted to examine Long COVID brain fog symptoms.
They found that sustained inflammation from a Long COVID infection was a partial cause of brain fog, but the infections had also disrupted the protective blood-brain barrier, and both factors together led to Long COVID brain fog. Importantly, they found that this disruption to the blood-brain barrier had caused whole-brain blood leakage from leaky blood vessels and consequently increased permeability in patients’ blood-brain barrier.
Additionally, this Long COVID-induced blood-brain barrier chicanery caused structural changes in patients’ brains; they had decreased size in the frontal and temporal lobes with significant cortical (brain cortex, the noodle part) thinning.
Also, because it physically changing your brain wasn’t bad enough, it increases inflammation while decreasing the adaptive immune response, the part of the immune system that can actually organize a comprehensive defense against the SARS-CoV-2 virus.
Furthermore, Long COVID decreases blood coagulation, so you keep bleeding from your leaky brain blood vessels longer than you should.
All of these things done by the virus contribute to the neurological brain fog symptoms of this condition.
However, though this is not mentioned in the paper, these effects likely make patients more susceptible to other opportunistic infections, especially brain infections.
The adaptive immune system is the heavy hitter, the special forces used against bodily invaders. Long COVID specifically shuts down this half of the immune system, essentially removing our most potent defenses against invaders. Good luck trying to fend off invaders with a proverbial immunological stick.
As we’ve discussed, the virus also pokes holes in the blood-brain barrier, a structure specifically designed to keep invaders out of the brain. After turning our defensive barrier into Swiss Cheese, I expect other invaders—bacteria, viruses, and fungi—to be able to access and infect the brain much more easily.
Though Long COVID may seem like a bleak prognosis, many patients have eventually recovered. For those who have not yet recovered, research is still ongoing, with hundreds of millions of dollars being spent on research into treatment.