COVID19 for BIO101: Understanding the Virus in Simpler Terms

Amherst College Science Center

People are dying at an alarming rate from the COVID-19 virus pandemic. Part of the reason is this virus affects the respiratory system heavily and the virus has an incredibly high transit rate. In other words it is very contagious. We don’t know too much about how the virus functions, however, we know a few things. Oh yea, and there is no vaccine out yet.

A virus is a protein that carries a form of genetic material. Either a DNA or an RNA. It can inject this DNA / RNA into another cell (called a host cell) and this causes the DNA/RNA to be replicated and made into more proteins through the process of transcription and translation. The proteins are more viruses that can not only take over the host cell, but also then leave/kill the cell and take over other host cells to do the same thing again.

The body has some of its ways of regulating the transcription and translation process, using for example positive and negative feedback loops that support or prevent, respectively, the making of proteins based on their concentration in the cell.

mPro is an enzymatic regulator, called a protease, that is a heterodimer that supports the production of the SARS-COVID proteins. However, there are some drugs that are being made to prevent (inhibit) the formation of mPro such as N3. There are also other inhibitors such as cinanserin or Ebselen, which has a low cyto-toxicity.

The body also has a system that prevent foreign objects from entering, hence the immune system. However, the virus looks very similar to a protein that is already in the body, which is why the protein can enter the body easily. I mentioned earlier that the protein affects the respiratory system, indeed the virus does this because when it enters the body, it targets the respiratory epithelial cells. It binds to a receptor that coats those cell’s surfaces called the ACE2 receptor. The virus is then allowed through the cytoplasm of the cell. When inside, it breaks down and allows its RNA to “run free” and create havoc. Transcription and Translation allows RNA to make “hundreds of thousands of capsid and spike proteins”(1) that are essentially more COVID-19 viruses. They leave the cell via the cell membrane, kill the host cell, and infect more other cells exponentially.

Testing for the virus is difficult because humans do not have natural antibodies that are designed to recognize the virus and then summon white cells that engulf and kill the virus. Currently, a mode of testing for the virus is RT-PCR, Reverse Transcriptase PCR. This uses a Reverse Transcriptase (RT) to copy the RNA into DNA and uses PCR (Polymerase Chain Reaction) to amplify the DNA and further break it down to determine the nucleotide sequence of the RNA. Samples are often taken via Nasal Swabs, however there is high demand and limited supply world wide.

Developing a viable vaccine takes time and also a lot of money (2). Unfortunately, we don’t have much of this. We also do not have much cooperation from people in the United States as there are people who refuse still to socially distance. At this moment, there are casinos, public beaches, barbershops, churches, restaurants, and other large gathering places, that are opening up their doors. This is partially due to ignorance and the “it cannot happen to me” belief. The other part is that the United States is getting a severe economic blow that has caused hundreds or thousands of people to lose their jobs and even their businesses. Another dimension of this is the desire for humans to have social contact and not be isolated for a long period of time with no apparent end.

Of course, this virus also impacts people at disproportionate rates. Homeless people are at high risk for contracting and also spreading the disease. Minorities in the United States are dying at higher rates than others. Essential workers, such as Doctors, Nurses, Techs, Facilities staff, are also being exposed at extremely high rates and hospitals are not uniformly equipped with PPE to guard against exposure.

A common question that is spreading about the death toll is: are the reported numbers true? Because of the lack of testing supplies, there are hundreds and thousands of people who are going unreported for the COVID-19 virus. On the flip side, according to Fox News, Dr. Debrah Brix has said that the government has said that all patient deaths in 2020 will now be reported as being due to COVID-19, regardless of the cause (3). However, discourse has arisen because Dr. Fauci and Dr. Birx, according to the Washington Post, have also responded that this indeed is not the case and that “There are plenty of reasons to believe that the coronavirus death toll is actually being significantly undercounted, in fact, rather than overcounted.” (4) So indeed the numbers of the death toll are still believed to be high.

In short, at the moment, our only solution to preventing the spread of the virus, is to social distance and stay away from people. Even better, stay at home. The virus has gotten so bad, that people are now being buried in mass graves. This isn’t something that the United States has had to do for a while. Until then, we await a vaccine.