zlacker

One thing I wonder is:

How did the UK virus suddenly get 17 mutations at once if it's not a new engineered release by someone?

I'm not a biologist, but that part had me wondering.

Any biologists here who want to explain for a layman?

>>skinke+(OP)
Not a biologist, this is not a biological question per se - all viruses and bacteria mutate over time during replication. It's a question of statistics rather... When you have 100 infected individuals and a virus that mutates in 1% of infected people (note: this is a random number, no idea what the actual mutation rate of coronavirus is), you'll end up with one mutated version. When you have 100k of infected people, you'll end up with 1k mutations that are spreading out and (essentially) self-selecting. And when you hit 1M of infected people... it's 100k mutations.

That is why it would have been important to keep infection rates down until there's a vaccine - because it is more than likely now that there's a strain of coronavirus somewhere that has a different spike protein and so is not caught by the existing vaccines.

>>mschus+p1
But how did one new strain suddenly amass 17 previously unseen mutations?

Normally we should have sampled a number of strains with fewer of the same mutations, shouldn't we?

>>skinke+f3
Not an expert here, but there probably are many other strains out there with fewer mutations (and some with more). Most of them residual because they don't provide a clear advantage. The reason we know about this 17-mutation one is that this specific one turned out to have such an advantageous infectivity that it's displacing all other strains and becoming the dominant one.

>>skinke+(OP)
Not a biologist. But this interesting article [1] in Science Magazine, describes a possible route how SARS-CoV-2 may acquire multiple new mutations: Immunocompromised patients with long running infections. Two cases have been independently reported in the UK and US. The patients have been infected for a duration of 101 and 154 days respectively. In both patients the virus acquired multiple new mutations, both were eventually treated with antibodies, but have still died in the end. It looks like a weak immune response which is not sufficient to clear the virus, may help the virus by giving it the time needed to further adapt to it's human host.

[1] https://www.sciencemag.org/news/2020/12/uk-variant-puts-spot...

>>skinke+(OP)
I'm not a biologist either, but I've been told recently by someone who's likely to know what he's talking about (albeit also likely to be a bit "rah-rah Britain") that the UK is doing far more genetic sequencing of the virus than the rest of the world, which would explain why it gets noticed more in the UK.

>>jng+q6
Thanks.

That would make sense, if it was the 17th mutation that (possibly together with the rest of the mutations) gave it this advantage.

>>twicet+7t
Thanks! Makes sense that it gets found in Britain. Still seems like a large number of mutations.

>>skinke+f3
The problem is most countries don't sample - they put people through a PCR test and then send them off their way. The UK also does somewhat-regular genetic sequencing of positive tests, precisely to spot new mutations.