Naked Science Forum
Life Sciences => Physiology & Medicine => COVID-19 => Topic started by: set fair on 12/02/2021 16:10:26
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Lockdown, masks, distancing, hand washing are all things which reduce transmission, these measures put an evoluytionary pressure on the virus to become more infectious. If there were more infectious variants than D614G we would have expected them to have emerged and spread months ago.
The success of new variants occuring now have to be in response to the evolutionart pressure of a significant proprtion being immune to D614G. That pressure favours resistant variants. They will appear to spread faster because they can infect more people, ie with say 30% immunity in the population the D614 will effectively reduce in infectiveity by about 30%, making the new variants appear more infectious. This is just the virus trying to escape our immunity. There's nothing surprising about this, on the contrary it's exactly what we would expect.
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If there were more infectious variants than D614G we would have expected them to have emerged and spread months ago.
The probability of mutations happening is proportional to the number of people infected.
- So countries that let it get out of control (large number of infected people) created the conditions under which new variants will proliferate
- Some of these variants will evade our newly approved vaccines (or at least, render them less effective)
So, even after everyone is vaccinated, we will need to maintain some social distancing + masks + hand washing + contact tracing + quarantine to keep the mutants under control too.
- And we will need to vaccinate susceptible pets & agricultural animals, to suppress an animal reservoir which might produce mutants that have not been seen in humans
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There have been a couple of COVID-19 cases in hospital where people never managed to clear the virus, so they developed a chronic infection lasting many months, which generated a large number of mutants - some of which started beating advanced new therapies like monoclonal antibodies.
Those patients ended up dying, but some of those variants could be extremely dangerous if they escaped into the community.
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There's nothing surprising about this, on the contrary it's exactly what we would expect.
Almost everybody knew this
There's one unfortunate exception.
https://www.thelondoneconomic.com/news/reactions-as-harding-claims-nobody-could-have-predicted-covid-virus-would-mutate/03/02/
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Virologists know a bit more about their subject than planatary scientists - lots of surprises but at least most virologists are circumspect, I don't think they knew enough to predict how and why CoV2 might evade immunity, but it looks like falling antibody levels/fading immunity from those infected in the first wave is the driver here - 3 new variants all with some resistance emerging at the same time.
Makes some sense then, to vaccinated potential spreaders - supermarket workers, bus drivers,teachers ahead of the oldish (which is me).