Why coronavirus kills more old people than young - possibly ... What about pre-existing conditions?
Well obviously pre-existing conditions I mean stands to reason doesn't it? But apart from pre-existing conditions, why does coronavirus kill more old people than young - possibly.
I was listening to a scientist on the radio the other day describing how Covid-19 which is part of the coronavirus family could be possibly fooling the immune system and making it think its a virus that the body has dealt with before, so it leaves it alone initially.
This could explain why the virus appears to affect older people worse than younger people and children. That's not to say that younger people and children don't get affected, they do. Just a lot lot less.
There are now 7 human coronaviruses.
4 common ones
229E (alpha coronavirus)
NL63 (alpha coronavirus)
OC43 (beta coronavirus)
HKU1 (beta coronavirus)
3 that cause more damage
MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS)
SARS-CoV (the beta coronavirus that causes severe acute respiratory syndrome, or SARS)
SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19)
The last on the list SARS-CoV-2 is the latest to join the club and its possible, but not proven yet, that it may have some, let's call it special stealth capabilities.
But the theory makes sense, well to me at least. There are plenty of links below for anyone interested in scientific names etc. I've tried to write this so I could understand it and therefore hopefully others.
So here's the theory
Over the years us oldens get exposed to all sorts of bugs, viruses, etc. Flu would kill a lot more people if we hadn't built up immunity to it over the years and we still need a vaccine.
The 4 common coronaviruses above we have also built up immunity to over many years. So our bodies in general recognise these coronaviruses. If they try and get in, the immune system checks them, goes oh right we know you, we already have some troops trained to deal with you, don't go away they'll be along in a second.
Now along comes SARS-CoV-2, looking very similar to the 4 common coronaviruses, so the immune system goes OK we know you, we'll send some troops we've already trained to deal with you. The normal response is not set off and the body doesn't make a specific set of troops to deal with the invading virus, it thinks it's already done it. But SARS-CoV-2 is not like the other coronaviruses.
SARS-CoV-2 carries on on its journey looking for cells to invade and is hit by all the troops the immune system has but they have no effect as they don't have the right tools to do the job. By the time the immune system realises its been duped SARS-CoV-2 has already got a hold and the specific troops being made now have a real battle on their hands.
This would explain why older people get it worse. The more of the 4 common coronaviruses we have had the easier it is for SARS-CoV-2 to sneak through.
Children and younger people however have had less exposure to the 4 common coronaviruses, maybe none at all. When SARS-CoV-2 wanders in, the body immediately makes a specific set of troops to fight it and the initial response is so very important is stopping SARS-CoV-2 from getting a foothold on the beaches. Which means you end up with mild symptoms.
Nothing is every 100% and yes children have died, maybe they had already had some of the 4 common coronaviruses, who knows.
As I said above none of this is proven concerning SARS-CoV-2.
Some viruses exist that do what is described above and SARS-CoV-2 could be one of them, time will tell I guess.
Obviously as already stated there are other things like preexisting conditions to consider. Mainly, but not exclusively in the elderly.
LINKS
How Some Viruses Protect Themselves From the Immune System's Efforts to Stop Infections
How Viruses Can Fool The Immune System
Virus tricks the immune system into ignoring bacterial infections
How herpes virus tricks the immune system
Human Coronavirus Types
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