COVID-19 or Corona Virus or SARs-CoV-2 can be caught in multiple ways through the droplet of an infected person's cough, sneeze or breath. Once the body has encountered the virus, one will start to feel the symptoms within 2-14 days. Some symptoms include:
Fever
Continuous coughing
Shortness of breath (dyspnea)
Loss of taste and smells and in some cases more...
Click here for the government guidelines if you think you may have the virus or had it within 2 weeks.
First, before talking specifically about corona, one needs to know the basics of how a virus works. Here is the structure of a virus:
When the virus encounters a cell, Viruses will have these attachment proteins on the surface and the body cell, which is soon to be infected, will have receptors on the surface. These attachment proteins will have a specific 3D shape that is complementary to the shape of the receptor of the cell it is infecting. They will bind and this will allow the virus to enter the cell. Once inside, the virus will inject the genetic material into the DNA of the cell and this will change the information of the host cell to produce components of that virus and so more viruses can be produced within the cell. Once enough viruses have been made in the cell, it will burst and the viruses will infect other cells and carry out the process over and over again.
Now with COVID-19, there is a specific receptor on the host cell called ACE2 that the virus will bind to. Because COVID-19 enters through the respiratory tract it will most likely infect those cells first. In normal cases it infects cells deeper in the lungs, such as the alveoli and around that area as those cells in the lower airways have more ACE2 receptors. So this is why Corona is very much linked to respiratory problems.
When the virus has infected enough of those cells, there will mostly be high areas of inflammation and so it will become increasingly harder to breath, causing shortness of breath (dyspnea). This can also cause Pneumonia as the alveoli are more susceptible to infection.
On the walls of the airways leading to the alveoli we have mucus that is produced and this mucus serves to trap any dust or pathogen that may find its way into the lungs. As one may be infected with the virus, some of the viruses may be caught in the mucus and when they are caught, the mucus will be wafted back up through the respiratory tract by cilia which are hair like structures. When expelling this we cough to remove any dust or pathogens from the body. When the cells are infected we will accumulate more and more of the virus in these areas so it will cause constant irritation meaning more and more coughing.
In even more serious conditions some may develop ARDS (Acute Respiratory Distress Syndrome). This is after the tissues and blood vessels in the alveoli are damaged and debris starts to fall in the alveoli and block it, making it even harder to breath. Also, it means that one will be breathing faster to make up for the loss of gas exchange in the damaged alveoli. This will cause the heart to work faster, as less oxygen is in the system, so the heart still needs to supply less oxygen at a faster rate to meet the demands. In most cases the NHS would use a ventilator.
We can start to see that there will be less oxygen around the body, meaning less oxygen to muscles so less respiring cells so less energy made and so we become much more tired.
Because of the lack of gas exchange we may have a higher concentration of CO2 in the blood and this will cause a more alkali effect on the blood cells, so they will change shape which means it will be harder for the proteins in the blood cells to pick up oxygen in gas exchange. Using a ventilator is very important in these cases as we need to increase the oxygen saturation in the lungs so it will help return the pH to the right conditions and so the shape of the proteins in the blood will return to the right shape for oxygen to be picked up.
When we return home it is essential that we wash our hands with soap as this destroys the outer layer of the virus. simply, the soap is made to break up the lipid bilayer of the virus which makes up the membrane and this means that water can enter the virus and it will burst, destroying it.
This is the first step, to understand how the virus works, it makes it much more easier to find special chemicals to kill it or special drugs to vaccinate us against it.
A step in the right direction !