How Does The Coronavirus Kill You?
Coronavirus is one nasty thing. Its capability to spread is already incredible and yet with the right mutations it will spread even faster. Calculating the disease’s ability to spread is called the basic reproduction number (R). For the coronavirus the R is between one and two, which means that an infected person will infect one or two new people.
UPDATE (07.07.2021): there is a rise of mutations that are increasing the spread of the disease
Which viral disease is the most contagious (has the highest R number)?
It’s measles with an R-value of up to 18. This means that one person on average will infect 18 others. This makes it the most contagious viral disease and stopping the disease is only possible by vaccinating.
Origin of viruses
Viruses are extremely old. Their origin is still a mystery — perhaps they are the precursors of life itself or perhaps they were once living organisms who specialized in infecting other living beings.
One thing is sure: they can’t live without living organisms. Viruses are obligate intracellular parasites, that can’t survive outside of living cells. This is because they do not carry out metabolic processes (like generating ATP molecules) and require the cell’s machinery to reproduce.
We know that viruses are extremely diverse, but they all have certain things in common:
1. They are extremely small: if you enlarged the virus for 4000x it would barely be a size of a poppy seed (if you increased your hair for 4000x it would have a diameter of 30 centimeters — 1 foot)
2. They can only replicate inside living cells.
3. No known virus contains ribosomes, a necessary component to produce cell’s proteins.
4. Every virus has a specific way to enter a cell: usually they bind to a specific protein on a cell’s surface which helps them to get inside.
FUN FACT: some people are immune to HIV infection
HIV requires a specific receptor to bind to a cell called CCR-5. Around 1% of Europeans have both genes for the receptor mutated — which makes them immune against the infection. Don’t risk it though, wear a condom.
The virus doesn’t want to kill you
Viruses need to follow certain rules if they want to be successful. To them, you are nothing but a place to make new viruses. But they don’t just invade and destroy host cells, they need them, they need you to stay alive. If they killed us all, they would have no more place to reproduce. They are walking on a very thin ice though — too deadly and they might disappear. Not deadly enough? Perfect! Now you know why you get sore throat and colds so often.
Coronavirus is somewhere in between. More deadly than an average virus and yet (thankfully) not deadly enough. It can survive, because it operates as a spy in enemy territory, passes its genetic material from cell to cell without activating the host’s immune response.
Why is coronavirus deadly
The new coronavirus is a respiratory virus, meaning that it can enter and invade your respiratory system. Some viruses tend to stay just in your upper respiratory tract, where the temperatures are a bit lower and some can infect your lower lungs. Coronavirus can do both, that is why some people get away with cold-like symptoms and some need extra oxygen.
Our immune system should defend us — even if it’s the first time encountering the coronavirus. The problem starts when the defense is insufficient, for example older people are often immunosuppressed. If nothing stops the virus it will continue to spread to your lungs and you will end up with pneumonia. When the damage is too big, you may develop acute respiratory distress syndrome (ARDS), meaning you don’t get enough oxygen.
The problem is that coronavirus uses specific receptors to enter the cells (angiotensin II receptors) that are widespread across the body. So, even though it’s a respiratory virus, you can develop other symptoms like diarrhea.
Conclusion
Although the virus doesn’t want to kill you, it just might (unintentionally). So, stay safe and protect yourself and the people around you.
1. Wiersinga, J W. PubMed. Pathophysiology, Transmission, Diagnosis, and Treatment of Coronavirus Disease 2019 (COVID-19): A Review. [Online] August 25, 2020. [Cited: January 16, 2021.] https://pubmed.ncbi.nlm.nih.gov/32648899/.
2. Farabee, M J. BIOLOGICAL DIVERSITY: VIRUSES. [Online] 2007. [Cited: 1. 16. 2021.] https://www2.estrellamountain.edu/faculty/farabee/biobk/BioBookDiversity_1.html.
3. M’ikanatha, N M, et al. Infectious Disease Surveillance. New Jersey: John Wiley & Sons, Ltd, 2013.