Covid-19 is the illness caused by the novel coronavirus SARS-CoV-2. The illness has been shown to affect multiple organs including the brain, heart, kidneys, eyes, nose, in addition to the lungs and gut. The damage it causes can be permanent, so even if infected people survive, the effects of the virus can linger indefinitely.
The pandemic that SARS-CoV-2 has caused has tested us severely. When will it go away, why does it keep mutating, why cant we just come up with a way to kill it or at least a vaccine that stops it in its tracks? What the heck is Dr. Fauci doing all day?
To understand any enemy, it is essential to know it's true face. For SARS CoV-2 it is better to think of it not as a single virus trying to get us, but instead more as an organism containing trillions of viruses, much as you are made of trillions of cells but hopefully people see you as a single person. It is more a viral cloud, containing more viruses than all the grains of sand in the world, ever evolving and adapting in order to increase its chances of passing its genetic material on to the next generation.
100 million novel coronavirus can fit on a pinhead. There are trillions upon trillions of the viruses out there and each one can make thousands of copies of itself given the chance. I'll say it again. When a single SARS-CoV-2 virus replicates, it produces over 10,000 prodigy.
The Sars-CoV-2's genetic makeup contains 29,903 base pairs, the chemicals that make up its genes. Accidents in assembling these base pairs can occur spontaneously, producing mutations. This occurs, despite the SARS CoV-2 virus possessing a proof-reader mechanism that looks for defective genes during replication and halts that error from being replicated. But despite this, the SARS CoV-2 virus does in fact mutate, albeit at a relatively slower rate than some viruses.
The vast majority of mutations are either harmless and do not cause a survival advantage, or are harmful to the virus itself. As such these viruses have no survival advantage and either die off before replicating or cause no significant change in the SARS-CoV-2 virus as a whole. But occasionally mutations occur that provide a survival advantage to the virus, and as you will see, this can dramatically change the makeup of the entire viral cloud.
The human genome contains 3 billion base pairs that can potentially mutate. Most of these mutations have little impact, some result in fetal demise, while a very few could provide a survival advantage if only we still lived on the savannah.
But here's the thing - even though humans have 100,000 times the number of base pairs that can undergo mutation as compared to the virus, when we replicate we produce 1-2 new humans in 70-80 years of life, whereas a single virus produces over 10,000 new viruses within hours of infecting a host. If just one virus mutates to produce a survival advantage - greater infectivity, greater vaccine and/or drug resistance, etc - and is lucky enough to replicate - it will produce 10,000 new mutated viruses. If their survival advantage gives them just a 1% replication advantage over 'regular' virus then these 1% would produce one million more mutated viruses above and beyond what normal viruses would do. Replicate 1% of those one million and we now have 100 million more mutated viruses than from non-mutated viral replication. You can see where this is going. As long as there is an abundant supply of relatively helpless hosts to invade, eventually the viral cloud as a whole will become comprised almost entirely of mutated virus at which point we say the 'virus' has genetically drifted or if the drift large enough - we say the virus as a whole has mutated.
The organism as a whole that causes Covid-19 is indeed shifty, evasive, and constantly morphing. It is difficult to know the face of this enemy as it is always changing. It is the combination of the virus being novel - never before seen by humans so it can potentially infect 8 billion human hosts relatively easily giving it the opportunity to mutate in order to evade immune responses to prior infection and vaccines, that comprises one of the most significant existential threats to humankind in our entire history and what keeps Dr. Fauci awake at night, I'm sure.
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