Chinese Whispers

[onthemove]

I'm pretty sure we're all familiar with Chinese whispers... person A says something to Person B, who then passes it on to Person C, who then passes it on to D,... E,... F and so on.

And at the end of the chain, the message is so garbled that it bears no resemblance to the original message.

Here's the thing... Chinese whispers 'work' because at each step of the process the message undergoes a little additional mutation each time, and these mutations then accumulate along the chain, resulting in a huge difference in the end message.

Here's what I don't get...

I've just seen a post on another thread, yet again mention "variant factories" or some such, and how these are evil and going to be the end of mankind. (I exaggerate slightly, but not a lot )

Apparently, it seems like the original variant of sars-cov-2 that was around in spring last year was less transmissible and possibly (a little) less deadly than the variants doing the rounds now.

Admittedly, we now have the vaccine. But even so, I'm not sure I understand the issue with variants.

Let me explain...

Imagine you are playing Chinese whispers, but instead of it being a chain...

A B C D E

You now have...

A B
A C
A D
A E

It's true that you might end up with 4 mutations, but these 4 mutations are likely to all be very close to the original "A", in contrast to the original chain where you'll still have 4 mutations (you still have mutations at each step), but as you go along the chain each is getting further from the original - as it's then a mutation of a mutated message.

So why is it that scientists seem to be arguing for a 'slow burn' (it's widely acknowledged we ain't getting rid of covid now).

Surely a slow burn means each infection passing to fewer people, but then hopping from person to person...

i.e. surely a slow burn is going to be more closer to this...

A B C D E

... than if you have a high R rate, with one person infecting many, in which case you'd have something more like...

A B
A C
A D
A E

There is already evidence that if you get Covid, that the antibodies are actually quite broadly protective even against new strains.

So if the concern is regarding mutations evolving, why isn't it better to go for a 'fast burn'? Surely a slow burn, trickling around the population is going to give the virus more opportunity to explore more evolutionary avenues?

I realise there are issues with hospital capacity from a fast burn.

And I realise we now have vaccines.

But those arguing for a slow burn, and stirring fear of mutations, don't seem to be arguing on the basis of it just being to manage hospital capacity, etc.

They seem to be suggesting that a slow burn is less risk in terms of mutation.

Which I'm just not sure I understand.

[XFool]

I'm pretty sure we're all familiar with Chinese whispers... person A says something to Person B, who then passes it on to Person C, who then passes it on to D,... E,... F and so on.

And at the end of the chain, the message is so garbled that it bears no resemblance to the original message.

Here's the thing... Chinese whispers 'work' because at each step of the process the message undergoes a little additional mutation each time, and these mutations then accumulate along the chain, resulting in a huge difference in the end message.

Here's what I don't get...

I've just seen a post on another thread, yet again mention "variant factories" or some such, and how these are evil and going to be the end of mankind. (I exaggerate slightly, but not a lot )

No. I think you are exaggerating a lot.

Apparently, it seems like the original variant of sars-cov-2 that was around in spring last year was less transmissible and possibly (a little) less deadly than the variants doing the rounds now.

Admittedly, we now have the vaccine. But even so, I'm not sure I understand the issue with variants.

Let me explain...

Imagine you are playing Chinese whispers, but instead of it being a chain...

A B C D E

You now have...

A B
A C
A D
A E

It's true that you might end up with 4 mutations, but these 4 mutations are likely to all be very close to the original "A", in contrast to the original chain where you'll still have 4 mutations (you still have mutations at each step), but as you go along the chain each is getting further from the original - as it's then a mutation of a mutated message.

So why is it that scientists seem to be arguing for a 'slow burn' (it's widely acknowledged we ain't getting rid of covid now).

Surely a slow burn means each infection passing to fewer people, but then hopping from person to person...

i.e. surely a slow burn is going to be more closer to this...

A B C D E

... than if you have a high R rate, with one person infecting many, in which case you'd have something more like...

A B
A C
A D
A E

There is already evidence that if you get Covid, that the antibodies are actually quite broadly protective even against new strains.

So if the concern is regarding mutations evolving, why isn't it better to go for a 'fast burn'? Surely a slow burn, trickling around the population is going to give the virus more opportunity to explore more evolutionary avenues?

Perhaps a geneticist will be along in a minute? In the meantime you will have to put up with me.

Firstly I am not sure what exactly is meant by the terms "slow burn", "fast burn".
Secondly, I feel your Chinese whispers analogy is off beam. Why? Because you seem to be drawing an analogy between person to person Chinese whispers and the virus "hopping" from one person to another. But the viral mutations occur on reproduction of the virus in the cells of an infected individual - if I understand correctly. So variants can presumbly arise in just one individual, rather than only when they pass from person to person. Of course, more infected people, more reproducing viruses, more mutations.

It may be that with a population of people, all with different immune systems and having differing vaccination status, it is more likely for a more dangerous variant to arise. Presumably by selection of variants rather than any mechanism of mutation. I don't know.

We need a geneticist...

[tjh290633]

I'm disappointed. I was expecting a reference to "Send three and fourpence. We're going to a dance".

TJH

[Mike4]

I'm disappointed. I was expecting a reference to "Send three and fourpence. We're going to a dance".

TJH

Doesn't sound so good in newfangled decimal currency....

"Send 17p, we're going to a dance".

[servodude]

But the viral mutations occur on reproduction of the virus in the cells of an infected individual - if I understand correctly. So variants can presumbly arise in just one individual, rather than only when they pass from person to person. Of course, more infected people, more reproducing viruses, more mutations.

yup

every replication there is the chance of mutation
- normally the virus builds up in someone till the immune system gets its act together and wipes it out
- peaking at 10^9 to 10^11 virions at the max
- even with its relatively slow mutation rate there's likely at least one mutation in every infected person
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7685332/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7224694/

if you want the virus to have a chance to explore more "evolutionary avenues" you keep it in someone for as long as possible
that gives it the more chance of stumbling upon a trick to get round the defences, replicate with this and then be on-transmitted (with its new tricks)
- if you do that across enough people at the same time you'll start to see multiple variants arising in difference places


- sd

[Lootman]

But the viral mutations occur on reproduction of the virus in the cells of an infected individual - if I understand correctly. So variants can presumbly arise in just one individual, rather than only when they pass from person to person. Of course, more infected people, more reproducing viruses, more mutations.

yup, every replication there is the chance of mutation

if you want the virus to have a chance to explore more "evolutionary avenues" you keep it in someone for as long as possible
that gives it the more chance of stumbling upon a trick to get round the defences, replicate with this and then be on-transmitted (with its new tricks)
- if you do that across enough people at the same time you'll start to see multiple variants arising in difference places

OK, but what do we do with that information, assuming for now that it is correct?

The idea of the lockdown was to minimise infections because of the number of them leading to serious illnesses, hospitalisations and deaths. Until such time as vaccinations broke that link.

Now that we have seemingly broken that link, at least in the UK and the US, some people seem to be suggesting that we keep restrictions anyway, not because of what is actually happening for which there is any data. But rather out of some fear about what might conceivably happen in the future, as if every living soul out there is some kind of human time bomb.

And since there will never be a zero risk of mutation and variants, then what? Does that mean we wear masks and socially distance forever? Does anyone seriously believe that?

[DrFfybes]

Now that we have seemingly broken that link, at least in the UK and the US, some people seem to be suggesting that we keep restrictions anyway, not because of what is actually happening for which there is any data. But rather out of some fear about what might conceivably happen in the future, as if every living soul out there is some kind of human time bomb.

And since there will never be a zero risk of mutation and variants, then what? Does that mean we wear masks and socially distance forever? Does anyone seriously believe that?

I see the risk being that as cases are doubling every week or so, we quite quickly reach a situation where new mutations are more likely to arise. The vast majority of mutation don't 'take' - they're either 'Silent' (where the genetic change doesnt translate into a change in the viral proteins as several genetic codons can produce the same amino acid) or they can be terminal - ie the mutation stops the virus functioning. However, we have seen a mutation arise in Kent in the UK, with infection numbers not as high as many countries, which is more virulent. The big fear is the next mutation will evade the vaccine.

Keeping hospitalisations at a low level is much different to keeping the infection levels low, but something as simple as keeping masks in confined public spaces for a few more months would reduce infection levels until more people are vaccinated.

But on the plus side I'll not be mistaken for a Dogger next time I'm in a public toilet.

Paul