Our lives have been turned upside down with instructions to ‘stay at home’, ‘wear a mask’, ‘stay six feet apart’ and get a COVID-19 antibody test. We even have a new phrase–’social distancing’ that we had not heard a few months ago. So what is a coronavirus? Let’s start by understanding a virus.
What is a Virus and how does it make us sick?
What is a virus? Live Science calls a virus a “microscopic parasite.” Viruses are smaller than bacteria. For example,10,000 polio viruses would equal one grain of salt. Viruses are made up of a nucleic acid, either deoxyribose nucleic acid (DNA) or ribonucleic acid (RNA).
When we are exposed to a virus, it is not a danger unless it enters our bodies. (Think masks and social distancing to avoid being exposed). Prime entry points for a virus to enter is our respiratory tract and open wounds. In the case of the coronavirus, mucous membranes of our eyes, nose and mouth, are prime entry points. When the virus enters our body, it attaches to body cells, hijacks our cellular activity and starts replicating (reproducing) itself. When the amount of virus cells reproduced reaches the level to make us sick, (called viral load by scientists), then we become symptomatic and ill.
There are over 200 viruses in our world. The common cold is caused by a rhinovirus. Another virus that can cause cold symptoms is a coronavirus. In fact, four common coronaviruses can cause mild cold symptoms in humans. But the cold-causing coronavirus is not the same virus as the one causing the COVID-19 illness.
So back to the original question: what is a coronavirus? A coronavirus gets its name from its appearance. By now, everyone has seen the pictures of a coronavirus. The protruding spikes of the virus looks like tiny crowns. The coronavirus spikes enable the virus to attach to cells in our bodies, begin to control the activity in those cells and reproduce more viruses.
SARS-CoV, MERS-CoV and COVID-19 cause illness and death
According to the Centers for Disease Control (CDC), three coronaviruses have spread from bats to people and caused life-threatening illness: SARS-CoV, MERS-CoV and and COVID-19. The SARS-Co (Severe Acute Respiratory Syndrome) emerged in Asia in 2003 and affected 8000 people with 774 deaths worldwide. MERS (Middle East Respiratory Syndrome) emerged in 2012 in Saudi Arabia and sickened 2519 people with 866 deaths. The COVID-19 virus emerged in November 2019 in China and during the first three months COVID-19 caused almost one million illnesses with 50,000 deaths worldwide.
The coronavirus which is causing the COVID-19 pandemic is a new (novel) coronavirus. The official name by the World Health Organization (WHO) announced February 11, 2020 is coronavirus disease 2019, shortened to COVID-19. ‘CO’ means corona, ‘VI’ for virus and ‘D’ for disease. Another name for this coronavirus you may see is SARS-CoV-2.
What happens in our bodies when we are exposed to COVID-19?
When the COVID-19 virus enters our bodies, attaches to cells and begins to reproduce, our immune system recognizes it is being attacked and begins to mobilize a defense to destroy the attacking virus. This generalized defense by our ‘innate (natural) immune system’ may cause early symptoms such fever, muscle aches and headache. At this point, our body is trying to mobilize immune system activities and slow or stop the virus from reproducing. The second response our bodies create is acquired immune response when our bodies produce antibodies which protect us from that specific virus or bacteria. (Think of plasma donations from recovered COVID-19 patients being donated and given to critically ill COVID-19 patients with good results). These two immune system responses protect the 80% of people who may have mild or no symptoms.
Early directives indicated that older people and those with immune deficiencies face a higher risk of COVID-19 illness. People with a decreased immune system response may not mobilize the body’s defense as quickly or as vigorously as normal which puts that person at risk. Another problem people with immune deficiencies may face involves an immune system malfunction where it continues to cause inflammation long past the time it’s needed. (This is called a cytokine storm and explains the organ damage that some people suffer.)
Why do people react so differently to COVID-19?
Physicians and scientists recognize that 80% of people have little or no illness from the COVID-19 while others become gravely ill and end up in intensive care units needing respiratory care, kidney dialysis and supportive therapies. Some die as the data shows; on May 1, 2020, 63,000 Americans have died from COVID-19..
One possible reason for the different body responses may involve our genetic code. Scientists believe that each person’s immune system response is determined by our inherited genes. As physicians have cared for multiple family members who all became seriously ill from the virus, they suspect that their inherited genes play a role in their body’s response to the virus.
Another determinant in which individuals become gravely ill involves chronic health issues. The term “pre-existing condition” includes comorbidities (two or more chronic conditions) which complicate the COVID-19 pandemic and increases the risk for serious illness. Three significant comorbidities are heart disease, high blood pressure and diabetes. People with these chronic health illnesses are identified by physicians as higher risk of serious illness if affected by COVID-19.
Because the COVID-19 is a new virus, there is much that medical experts still do not know. They have used the knowledge about the SAR-S and MERS viruses as a beginning point of knowledge. Reports from healthcare professionals caring for patients and some scientific studies are being done as efforts to verify what the COVID-19 virus does and does not do. Reputable medical websites such as CDC, WebMD, and Cleveland Clinic provide trustworthy and up-to-date information about COVID-19. We recommend that people use reputable websites rather than internet gossip when dealing with their health, including the COVID-19 pandemic.