The Science Behind COVID-19

With over 22 million cases, over 370,000 deaths, and a daily increase that surpassed 300,000 last Friday, the COVID-19 pandemic is undoubtedly one of the greatest challenges this country has ever faced. Even here at North Allegheny, there have been over 180 cases already, encompassing all 13 schools in the district. So how does this virus work, and why is it so dangerous?


First of all, what actually is COVID-19?

COVID-19 is a severe respiratory disease that is caused by a virus called SARS-CoV-2, a type of coronavirus. It’s important to note that SARS-CoV-2 isn’t the only coronavirus by far; coronavirus really refers to an entire family of genetically similar viruses, collectively known as the Coronaviridae, so called because they are covered in spike-shaped proteins resembling a crown. (“Corona” means crown in Latin.) At its core, a virus is really just a collection of genetic material encased within proteins; they aren’t even really considered living organisms because they don’t maintain a set of steady internal conditions, don’t grow, and can’t reproduce without a host cell to basically do it for them.


How did COVID-19 get its name? 

COVID-19 really stands for coronavirus disease 2019, as the “CO” stands for “Corona,” the “VI” for “Virus,” the “D” for “Disease,” and the “19” for 2019, the year in which it emerged.

The name of the actual virus causing COVID-19, SARS-CoV-2, is just a shortening of the name “severe acute respiratory syndrome coronavirus 2.” The “2” is there because COVID-19 is the second major outbreak of a coronavirus that is considered a “severe acute respiratory syndrome,” after the 2002-2004 SARS epidemic in China caused by SARS-CoV-1.


How does the virus causing COVID-19 enter the body?

The virus mainly spreads through respiratory droplets, which are particles of fluid like those expelled from a person’s mouth by coughing. Respiratory droplets typically travel a few feet through the air before they fall to the ground, which is why social distancing is being stressed with preventing COVID-19 transmission.

Airborne COVID-19 transmission, on the other hand, has to do with respiratory droplets that hang in the air for minutes to hours, becoming what are called aerosols. The danger with aerosols is that, unlike larger respiratory droplets, they can travel more than six feet through the air; this is especially a hazard with enclosed spaces that contain a large number of people. This is why it is recommended that large crowds should gather outdoors or go to someplace with effective ventilation, even if they are social distancing, since this allows aerosols to be circulated out and dissipated.

COVID-19 generally enters the body through the nose, eyes, or mouth. Furthermore, respiratory droplets always come from an infected person’s nose and mouth, as coughing, sneezing, singing, talking, or breathing can all be ways that the virus is transmitted. Masks are very important in this regard, as while they carry some protection against fluid particles entering the body, they more importantly keep fluid particles from leaving the body of an infected person, especially if they do not necessarily know they have the virus. It is for this reason that to truly prevent transmission, everyone needs to be wearing a mask when going out of the house.


What happens after the virus causing COVID-19 enters the body?

Once COVID-19 enters a person’s body, it begins by taking over a cell. It does this by taking advantage of receptor proteins, which are proteins embedded on the outside of the cell that allow the cell to detect and respond to whatever it comes into contact with. As mentioned earlier, one of the key characteristics of COVID-19 and other coronaviruses is that they have protein spikes; in COVID-19’s case, these spikes bind to specific receptor proteins called ACE2 and TMPRSS2, which are especially common to the inside of the nose. Binding to these receptor proteins effectively tricks the host cell, which would not be able to recognize COVID-19 as a virus, into allowing the virus’s genetic information and some of its proteins to enter. This genetic information is stored in the form of what is called ribonucleic acid, or RNA, which can be thought of as similar to DNA except that it codes directly for proteins.

Once COVID-19’s RNA has entered the cell, the virus is then able to duplicate itself. It does this by using the cell’s existing machinery, which would normally be used to synthesize the cell’s own proteins, to make the proteins making up COVID-19 and create copies of the COVID-19 genome. After the virus is done making copies and the cell is no longer useful, it destroys the cell and the copies go to new host cells to infect them. This strategy of quickly making copies and then destroying a cell makes COVID-19 what is called a lytic virus, in which a host cell is used to make copies of the virus before the copied viruses burst out, killing the cell.


What are COVID-19’s symptoms, and what are they caused by?

For starters, there are breathing problems  which are caused by the virus entering the respiratory system, causing irritation and inflammation. This inflammation comes as a result of your body recognizing the virus as a threat and trying to maximize blood flow; this is so that white blood cells, which are responsible for getting rid of pathogens like viruses, can get to the infected area as quickly as possible and fight it off. The immune system’s reaction can also come in the form of coughing, soreness, fever, sore throat, runny nose, nausea, or vomiting, all part of your body’s efforts to get the virus out of your system and all common symptoms of COVID-19.

More seriously, COVID-19 can result in pneumonia, which is when the tiny air sacs in the lungs, called alveoli, become inflamed. This can result in long-term breathing problems due to the damage in the lung tissue. Furthermore, imaging tests from patients who had recovered from COVID-19 have indicated injury to the heart muscle, even in individuals who experienced just mild symptoms; this could increase the chance of heart failure in the long term as well.

Whatever the case, COVID-19 is a serious disease with serious effects, and a better understanding of how the virus itself operates is invaluable in our efforts to combat it, whether for this school district, for this country, or for the world.