From PBS (and edited/amended by me)
Feeling confused as to why coronavirus is a bigger deal than the seasonal flu? Wondering if it’s all a bunch of hooie? Well, you’ve come to the right place! Let’s begin.
It all has to do with RNA. You’ll recall that RNA and DNA are the squiggly bits in our cells which control, well, everything. The “regular” flu is an “all human virus”. The DNA/RNA chains that make up the virus are recognized by the human immune system. This means that your body has some immunity to it before it comes around each year. You get immunity two ways: through exposure to a virus, or by getting a flu shot.
Novel viruses, ones that are not already in a personal relationship with our bodies, come from other animals (and sometimes aliens). The World Health Organization tracks novel viruses in animals, sometimes for years as they watch for mutations. Usually these viruses only transfer from, say, a pig to another pig in the case of H1N1 or bird to bird in the case of the Spanish flu. But, just like turtles, these little guys can mutate. Once one of these viruses mutates, and gets the ability to transfer not just from pigs to pigs but from pigs to humans, that’s not what’s technically known as “a good thing”.
Why, you ask? Because we have no natural or acquired immunity. The RNA sequencing of the genes inside the virus isn’t human, and the human immune system doesn’t recognize it so, we can’t fight it off. Basically it’s the RNA saying to our immune system “Nothing to see here, move along” and we believe it. Way to go, dumb immune system.
Of course, this is bad for the individual human who caught it but it’s not a huge deal for people at large. Sometimes the virus can only transfer from pigs to humans or birds to humans or whatever to humans for years and years, which means it’s only transmission from an infected pig or bird that we need to worry about. But eventually the virus can mutate so that it CAN transfer from human to human. Once that occurs - kerblooie! Now you don’t have to kiss a donkey to catch it - you just have to touch a doorknob that John touched a few minutes before or inhale the virus-laden droplet that Kathy exhaled earlier in the day.
Will it be super contagious? Just kinda contagious? Who knows? It depends upon how the virus has mutated. The swine flu (H1N1) could kill you but it didn’t mutate in such a way that it would kill you as easily as the Spanish flu. Its RNA mutated more slowly and it attacked its host differently. Yay for less deadly viruses!
And now, just in time for Christmas - covid19. It existed in non-humans only, for nobody knows how long. And then one day, at a market in Wuhan China, in December 2019, it mutated and made the jump from non-humans to people. Since I don’t know what it came from originally, lets just say it was a tufted gerbil. And remember, at the beginning, only tufted gerbils could give it to a person.
Cue the ominous music. In just TWO weeks it mutated again and gained the ability to jump not just from tufted gerbils to humans but from humans to humans. Scientists call the ability to mutate quickly “slippery”. This coronavirus, being in no way a “human” virus, hit the ground running because we have no natural or acquired immunity to it. Luckily, doctors have medicines for it … in an alternate universe. In this one - not so much.
The respirator problem you’ve read about? This particular mutated virus changed itself in such a way as to lead to great damage to human lungs. Hence the need for respirators. If lots of people are infected, there’s going to be a need for lots of respirators. Without them - death by suffocation.
And that, Little Adam, is why coronavirus is different from the seasonal flu, or H1N1 or any other type of influenza. This one is slippery and out to get us. Guess what, it has mutated again! Already! Now have two strains to deal with, strain s, and strain L. So - double the trouble in coming up with a vaccine. We really have no good tools to fight this directly. History has shown that fast and immediate closings of public places has helped in the past pandemics. Philadelphia and Baltimore were reluctant to close events in 1918 and they were the hardest hit in the US during the Spanish Flu. Google the Spanish Flu to see how bad a flu can be.
And don’t think “Ah well, it’s really only a problem for the oldsters”. Because … slippery! Who knows what evil lurks in the plans of covid19? How will it mutate itself next? Only the nobody knows.
Final word - take it seriously. Wash your hands. A lot. Wear gloves and masks if you’ve got them. Disinfect surfaces. #flattenthecurve