How COVID-19 Kills: New Study Explains the Mechanisms of the New Coronavirus

Infaction Blood Illustration

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections.

COVID-19, the disease caused by coronavirus SARS-Cov-2, has infected over 4 million people in 212 countries, of whom at least 272,000 have died. The ongoing economic and social impact of the pandemic is staggering, but despite a daily flood of news on the disease, few laypeople know that paradoxically, COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections.

In a new review article — explicitly targeted to non-specialists as well — in Frontiers in Public Health, a team of experts from Zunyi Medical University review the epidemiology, disease pathway, symptoms, diagnosis, and current treatment of severe COVID-19. They stress the key role of a potentially lethal overreaction of the immune system in the progression of the disease.

They explain step-by-step what is known about how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defenses to overshoot with a “cytokine storm.” This storm is an over-activation of white blood cells, which release too-great amounts of cytokines — inflammation-stimulating molecules — into the blood.

“Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome. The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus causing lung injury,” explains author Professor Daishun Liu from Zunyi Medical University, China.

The cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, blood clotting inside the body, extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs (“pleural effusion”).

White blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals (Multiple Organ Dysfunction Syndrome, MODS). This may worsen and shutdown the lungs (Acute Respiratory Distress Syndrome, ARDS) due to the formation of a so-called hyaline membrane, composed of debris of proteins and dead cells, lining the lungs, which makes absorption of oxygen difficult. Most deaths due to COVID-19 are therefore due to respiratory failure.

Liu et al. explain how in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to fight the symptoms, lowering the mortality rate through intensive maintenance of organ function, for example an artificial liver blood purification system or renal replacement therapy to filtrate the blood through mechanical means.

Especially important are methods to supplement or replace lung function, for example through non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe (if possible with the refinement of Positive End Expiratory Pressure, PEEP, where the ventilator delivers extra pressure at the end of each breath of keep the lung vesicles open throughout), the administration of heated and humidified oxygen via a tube in the nose (“transnasal high-flow oxygen”), or a heart-lung bypass.

The authors conclude by stressing the importance of preventing secondary infections: SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms. They advocate that this should be prevented with nutritional support, for example with probiotics — beneficial bacteria that protect against the establishment of harmful ones — and nutrients and amino acids to improve the immune defenses and function of the intestine.

“Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition,” concludes Liu.

Reference: “Severe COVID-19: A Review of Recent Progress with a Look Toward the Future” by Peng Xie, Wanyu Ma, Hongbo Tang and Daishun Liu, 13 May 2020, Frontiers in Public Health.
DOI: 10.3389/fpubh.2020.00189

7 Comments on "How COVID-19 Kills: New Study Explains the Mechanisms of the New Coronavirus"

  1. We keep hearing about the damage of inflammation- especially in these days of COVID. We also read about the anti-inflammatory properties of ginger and turmeric- especially in concentrated form such as the Zyflamend brand. Could increasing your intake of anti-inflammatory foods and herbs decrease the severity of the effect of COVID?

  2. Have not heard anything about why steroids would not help with the inflammation. Anyone know anything about that?

  3. Why not try the same treatment as if a patient has Vasculitis?

  4. Blatant advertising comment by Ralph.

  5. John Westerdale | May 13, 2020 at 7:13 pm | Reply

    Covid virus lives inside air passageways in lungs,not in blood… how would a blood borne immunity protect from airborne assault?

  6. The brain is a biological computer that can manufacture all of us and every living thing on Earth. Each species has a unique brain that takes the food the we give ourselves and makes us whatever we may be biologically programed to be. If the human body needs 9 different amino acids to create all the different kinds of cells that the body needs to make us then why not give the body the 9 different amino acids in every day meals to ourselves and see what happens because then that biological computer in our minds can then maybe have the cure for fighting the coronavirus and all it needed was the combination of all those 9 amino acids in our food daily to make the cells to overtake the damage that the coronavirus can cause. There is a recipe for a food dish called Adelynn’s Miracle Beans recipe that has all the 9 different amino acids as well as many other nutrients the body needs. Perhaps if we were to give those that are sick from coronavirus 2 servings of this Adelynn’s Miracle Beans recipe daily 5-6 hours apart and also give 2 Centrum equivalent vitamins with a bean meal 5-6 hours apart. This will give one’s body all the proteins, vitamins and minerals that a human body needs to create any kind of blood cell. Maybe the human body will figure out a way to kill the coronavirus as well as other flues and colds if we give it the ingredients for it to do so! Someone try it. It beats dying or suffering from the illness. I know that taking 2 Centrum equivalent in one day with a meal 5 hours apart does help one get rid of the flu and colds because I have been doing it for 25 years and it always help me stop getting sicker every time I felt like I was getting the flu. So maybe eating Adelynn’s Miracle Beans and taking the vitamins will help make people with the coronavirus get better.

  7. muhammad rosyid | September 7, 2020 at 7:02 am | Reply

    covid 19 white blood cells attack

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