How much further can covid mutate?

[Thelm]

I’m just wondering. Is there a limit as to how far a virus can mutate? Are we going to still be in a race to contain it in five years time?

I just don’t know how this will end.

There's no limit. Think of the fu. The vaccine changes every yr.

www.bmj.com/content/370/bmj.m3563

Multiple studies in multiple countries finding immunity to sars-cov2 in people never exposed to covid. I am looking for the other study using SARS samples...

Sorry, this is a huge backtrack to much earlier in the thread, but I don't understand about boosters at all.

I always thought the flu vaccine worked that you gained immunity to all the strains (variants?) you were vaccinated against, it just didn't work ongoing because there were different strains the following year, not that you lost existing immunity. So if you have it for 10 years and each one has 3 types, you have some immunity to 30 different types of flu. Which doesn't help at all when you encounter number 31, unless it happens to be very similar to one of the others.

I don't understand the logic of each booster being less effective. Is it because the information I have about flu vaccines is wrong, or is sars very different in terms of vaccine response?

@Lostinacloud

www.bmj.com/content/370/bmj.m3563

Multiple studies in multiple countries finding immunity to sars-cov2 in people never exposed to covid. I am looking for the other study using SARS samples...

I suspect this is how immunity works at large.

Although it’s somewhat surprising to me that we’re only now learning it.

If it’s accurate, then Cov-19 is a blip, and even the variants will cease to be a threat. At some point we’ll stop tracking them proactively and Cov-19 will fade from our memory.

I think Cov-19 is magnified in our perception because of the internet, media and social media, and hugely advanced scientific capability competent with anything we had even 20 years earlier.

The Spanish, Hong Kong and other major flu outbreaks were significantly different from endemic flu. Sometimes they arose from animals again e.g. swine flu, bird flu. These are so different we refer to them as different strains , whereas the changes in covid19 are still relatively small so we call them different variants.

Thankyou. That is very clear and a great explanation. I hadn't even clicked we differentiate strains and variants.

"Living with it" means a world with a substantially reduced life expectancy.
But we live with many diseases which are far more deadly than covid. Tuberculosis, measles, diphtheria. People don't die from them because we have vaccines and treatments. We have vaccines and we will have more and more treatments for covid.

[quote SallyBasingstoke]Chances of zero covid close to zero says professor whitty , what are your qualifications @chesirecat99 to say otherwise?

www.mirror.co.uk/news/politics/chances-wiping-out-coronavirus-close-23782556[/quote]
I didn't say that I subscribe to the view that zero COVID is the best strategy or anything about how realistic it is, I was pointing out that there are plenty of scientists that do consider it to be the best strategy in response to your rude question to strangeshapedpotato

Why do you talk about zero covid when any scientist in the world would laugh at you for talking idealistic nonsense that is not realistic

@Lostinacloud

I don’t think that is the same study strangeshapedpotato. It was carried out last year and concerned t-cells because they live inside a human cell and so detect any virus that attaches itself to a cell receptor so it can get inside the cell. Antibodies don’t deal with that type of cell attack.

Please post a link to the study you are referring to.

@SallyBasingstoke

Professor whitty top medic graduating from oxford says zero covid close to impossible

A mumsnet poster called cheshire cat says otherwise- who to believe

Zero Covid would have been possible if Johnson had listened to the scientists in February 2020.

Instead he decided to let it rip.

Zero Covid would have been possible if Johnson had listened to the scientists in February 2020.

Which scientists? SAGE?

I’d say Whitty knows his stuff

Becoming a milder virus is not really on the cards.

Why not? A virus doesn't have to be deadly to be successful. Look at the common cold Coronaviruses. Provided they can spread to new hosts and keep doing so, they're successful. There's every chance SARS-COV-2 will become milder.

www.pharmacytimes.com/view/study-results-suggest-sars-cov-2-could-become-mild-seasonal-virus

We shouldn't be comparing coronaviruses to influenza viruses. They replicate differently. For starters influenza viruses enter the cell nucleus and use the host's replication machinery there. Also, their genome is segmented. There's lots of info out there on Influenza viruses you can look up and compare with SARS-COV-2. Flu viruses mutate far more.

Cabbage would be a nice name change 😂

@jumpbounce

Some mutations may also be positive mutations which have much lower transmission etc.

A mutation that didn't spread as well as the mutation it originated from will get squeezed out of existence very quickly as it will be out-competed.

Why do you pretend a super vaccine that covers all variants of covid ( thousands of them such as the common cold which has never had any vaccine) will come out when flu vaccines cant do this having had decades of research where any flu vaccine is at best only around 60% effective?

I'm presuming she's referring to the development of mRNA technology used for the Pfizer and Moderna jabs.

www.health.harvard.edu/blog/why-are-mrna-vaccines-so-exciting-2020121021599

@ChocOrange1

"Living with it" means a world with a substantially reduced life expectancy. But we live with many diseases which are far more deadly than covid. Tuberculosis, measles, diphtheria. People don't die from them because we have vaccines and treatments. We have vaccines and we will have more and more treatments for covid.

We don't "live with" any of those diseases in the UK. They're all contained with zero- case plans in place.

In 2019, TB infected less than 5000 people in the UK and there is an active strategy to completely eliminate it.

Measles has even fewer cases (although it's on the rise). We had actually eradicated it as far as the WHO were concerned, but then vaccination rates fell so we got a few clusters re-emerge. Again though, it's not something we live with as our herd immunity to it is very good.

Diptheria is even fewer cases still - it's almost unseen in the UK thanks to vaccination.

In fact, the Western world has pretty much tamed every infectious disease more serious than influenza in order to get us to this stage where we live so long. We've done so either by vaccination reducing the likelihood of someone getting infected to pretty much nil, or as for example is the case with AIDS, using public health measures and education to control the spread until the risk is quite low.

Virus treatments are pretty limited incidentally - we've managed to find a few things that reduce the death rate from what it was initially, but anti-virals are REALLY REALLY hard to make and it's very unlikely we'll come up with one for covid any time soon. Vaccines are by far the preferred route, but they can't control it all by themselves as the Delta variant is so clearly demonstrating.

So, if there were millions of cases of Measles every year, but it wasn't a problem due to vaccines, you might have been making a valid comparison... but that's not the case. We jump on every outbreak and squash it completely. Until we start doing that with covid, we'll always be playing catch-up with the virus, and this nightmare is going to go on and on.

Becoming a milder virus is not really on the cards.

The virus' only goal is to propagate itself... Whether it causes severe, moderate or mild illness, or nothing at all, is irrelevant to its progress, unless it becomes sufficiently deadly that it kills off its "victims" before it can spread.

@SallyBasingstoke

"didn't say that there is no evolutionary process to become less lethal, she said there is no evolutionary pressure. Nor did she say that there is never any evolutionary pressure for pathogens to become less virulent, just that there wasn't any for SARS-CoV-2. You need to revise natural selection"

Are you really trying to split hairs over there is no evolutionary process to become less lethal and there is no evolutionary pressure lol?

Once again, the longer a virus is in a hosts body, the more it is likely to infect others so mortality isn't the key factor , transmissability is

Aaargh... I'm not splitting hairs.

If giraffes ate only grass do you think they would have evolved to have long legs and long necks? No, because there would be no advantage for them to have long legs and long necks. There is no evolutionary or selective pressure. However, they eat leaves on trees, so long legs and long necks mean they get more food, so they are healthier, therefore they will have more reproductive success than giraffes with short necks, they will pass on their long neck genes to their offspring so eventually there will only be long necked giraffes. If there is no advantage for a virus to become less virulent, it won't be selected for, it won't out compete more virulent variants.

Please read the very easy to understand link I posted earlier. It explains Anderson and May's (who, incidentally, taught me epidemiology at Oxford, as you were asking about my qualifications) trade off theory about the balance between transmissibility and virulence.

@SallyBasingstoke

" I was pointing out that there are plenty of scientists that do consider it to be the best strategy in response to your rude question to strangeshapedpotato"

Im not interested in your dodgy links to new zealand or Australia which is 30 times the size with half the population. Im interested in the Uk which is one of the most densely populated countries in Europe and you laughably claiming you believe zero covid is impossible disagreeing with an Oxford graduate leading medical advice who disagrees. There aren't plenty of sicentists at all who believe zero covid is viable, stop the lies and nonsense

I haven't linked to anything about New Zealand or Australia

I linked to articles from independent SAGE, an easy to understand article by academics from the University of Bath about why SARS-CoV-2 might evolve to be more virulent, the BMJ.