At first, the coronavirus infects the respiratory tract and the lung cells especially. The degree of infection varies from one person to another. In other words, some people will experience minimal consequences with hardly any symptoms while for others the outcome will be serious and at times fatal.

The coronavius disease is known as COVID-19. 

This article aims at explaining what happens to people's lungs when they get coronavirus and, in severe cases, how it may compromise the body's oxygenation and its ability to rid itself of the carbon dioxide (CO2) that is released by the lung cells.


Lack of oxygen and its consequences

We are all aware that a lack of oxygen in our bloodstream alters the functioning of our body's organs. Some of those damages may be irreversible and cause death.



The consequences of an accumulation of carbon dioxide

An accumulation of carbon dioxide in the bloodstream poisons our organs and acidifies our blood, so to say.


The lungs and their functions in respiratory system

Understanding the possible consequences of being infected with the coronavirus, COVID-19, calls for a thorough review of the functions of the lungs in the respiratory system.


Understanding the structure of the lungs    

The lungs are a pair of spongy organs. They are made up of a multitude of microscopic air sacs called alveoli. There are over 600 millions of them inside the lungs. 


What is an alveolus?

A pulmonary alveolus is about 0.2 mm in diameter. The alveolar walls are lined with a very thin layer of cells. The pulmonary capillaries cover all the alveoli.

A pulmonary alveolus is a hollow cup-shaped cavity found in the lungs. Its outside surface is covered with capillaries and its inside surface is lined with thin pulmonary cells called pneumocytes.

A microscopic "sheet" separates the pulmonary capillaries from the pneumocytes. This structure enables an extremely efficient exchange of oxygen from the lungs to the bloodstream. At the same time, carbon dioxide passes from the blood to the lungs and is expelled out of the body.


The pulmonary cells, the pneumocytes, are the primary targets of infection

The primary targets of the coronavirus are the pneumocytes; with its tiny tentacles, the virus grips the surface of the pneumocytes and invades it. Once inside, the virus takes control over the cell's functions.

A cell is much like a factory. It is made up of all the elements that are required when building various proteins of the human body.


Genetic material and the coronavirus

So, the virus is now inside the cell it infected with the genetic material that is needed to create a limitless number of viruses.

The cell is industrious and soon after bursts open and overflows with new viruses that are free to migrate and invade other cells.

The replication carries on.


An intruder in the house!

When the pneumocytes are infected, the body feels that something is wrong... an intruder is detected!


The struggle starts in order to fight off inflammation 

The body offers resistance to prevent inflammation.

The combat cells arrive on the scene to absorb the viruses, but they are outnumbered and they invade more cells. The inflammation sets in.

The human body does not have adequate immunity or a sufficient amount of antibodies to quickly win the battle.

The fight will last a long time and will not be effective. Meanwhile, the inflammation may have increased.


The passage of oxygen and carbon dioxide into the blood becomes difficult

Picture a badly sprained ankle. The swelling is such that it is hard to see its normal shape.

Now imagine a similar situation in the case of the microscopic layer set between the pulmonary cells and the capillaries. While the oxygen and carbon dioxide used to easily go through that microscopic separation, now both the air and blood have to pass through a thicker surface. This has become an insurmountable obstacle, a solid wall.

The patient needs air, he is suffocating. He is in respiratory distress, breathing is harder and tiredness sets in. More oxygen is needed and a ventilator becomes indispensable in certain cases.


The ventilator

Breathing may become very difficult and excessively tiring for the patient. He feels exhausted, his condition becomes critical.

A ventilator is a life-support apparatus that mechanically helps the patient breathe, improves his oxygenation, allowing him to rest. The bedside machine helps pump oxygen through a tube into the airways, lungs, and entire body, and provides support in alveoli expansion.  

The ventilator is removed once the patient's lungs are able to regain function.

A ventilator has its limitations, it does not replace the lungs. In a case where the sickness is so severe that the oxygen and carbon dioxide exchanges are no longer possible, hypoxemia and a carbon dioxide accumulation set in and compromise the patient's normal life. Death is inevitable.


Prevention is crucial

It is true that the majority of COVID-19 victims will recover from it without major sequels.

However, it is also true that some patients will require extensive care, support from a ventilator, etc., and that others will die.

The best treatment is and remains prevention:

  • sneeze and cough into your elbow
  • wash your hands often with soap
  • follow the rule of social distancing
  • at best, stay home.


Do the maths

When a COVID-19 victim contaminates 2 people, and those infect 2 more individuals and so on, after 10 such contaminations, that first person will have spread the disease to 1,024 other people. The consequence is even worse if the actual mortality rate is at 3%; it is equivalent to 30 deaths.

Keep your distance and comply with the basic social and hygienic measures in place. Make sure the people around you observe them as well.


The impact of vaccination

Vaccination does not prevent coronavirus from entering the respiratory tract. There is no sign that says: "This person is vaccinated, go away!"


The intruder arrives

The vaccine becomes effective as soon as the intruder enters our house.

Our surveillance center recognizes the enemy. The defense will be better orchestrated and will fend off the collateral damage mentioned above.


The "immune police" recognize the intruder

First, the immune police capture the intruder and identify it. Then, they look for its name in their records. This is when vaccination, or the person's recently acquired immunity, is extremely important and makes all the difference.


Antibodies quickly come into play

A production of antibodies to fight off the intruding virus is the required immune response.

The immune system is ready to cope with the situation and millions of antibodies will go into action. The enemy will be neutralized within the next few days.


The impact of antibodies on the virus

As mentioned at the very beginning of this article, proteins on the surface of this type of virus bind to receptor proteins on pulmonary host cells.


These molecules, or small cellular magnets, are antigens.

Antibodies are the perfect response to antigens. They join together harmoniously, much like in the yin and yang theory.

After the antigen connects to the antibody's surface, the virus can no longer infect, and it is destroyed by macrophage cells acting as housekeepers.


A benign infectious spectrum and a low risk of contamination

The threatening and much feared outcome of a coronavirus infection will not materialize, the patient having little or no sequels of his illness.

In other words, a marked decrease in the amount of viruses produced in the respiratory tract means that when a person speaks, sneezes or coughs, he or she expels far less infected droplets.