 Poster: A snowHead
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| snowdave wrote: |
| Grinning wrote: |
| we do not observe the variants that cannot infect us so cannot multiply so go extinct. |
Maybe that Darwin chap was onto something with his natural selection theory...  |
Mmmm! So perhaps this Covid Malarkey will wipe out those pesky ignorant Frenchies and we can all have holiday homes in Franceland like @weathercam
On a serious note I think that the French Government, and Macron particularly, should be charged with criminal incompetence. Is it not inevitable that all senior French Government Ministers get charged as criminals after office.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| Quote: |
In one day, yesterday, the UK gave around 12% of France's overall total vaccines.
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I suspect they didn't give them a single on. Companies in the UK (probably Swedish/UK ones) may have supplied them to France, but I bet they got paid for it, or will be paid for it.
A quick qestion - are there any vaccine manufacturing plants in France? We know there some in Belgium and Netherlands due to their reported problems and Italy because they are refusing to export some to Austrailia, but I've haven't heard anything about France.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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@johnE, I don't think that's what @ringingmaster meant (unless you were joking)!
I think @ringingmaster meant that the number of vaccines the UK administered yesterday (to its own citizens) is equivalent to 12% of the number of vaccines France has administered in total so far (to its own citizens).
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| johnE wrote: |
| A quick qestion - are there any vaccine manufacturing plants in France? |
There is Sanofi, their vaccine didn't work.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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@johnE, like @rjs, said there's didn't work (apparently they weren't prepared to do the overtime  ) just kidding...... however i believe they are using there plants to make some of the other vaccines the did work, not sure which ones though
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@JamesHJ, it was actually yesterdaythey did over 800k but the last 3 days (thurs-sat) uk has done just over 2.2 million jabs (80% roughly first dose)
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My sister lives in Paris and works in third world health (AID'S). She sent me this yesterday.
Went to local vaccination center today. Interesting public health front line research! It was closed! Opens 2-5pm only. A few v elderly people turning up in taxis who can’t book online then left again as the place was closed. No signposting on any streets to show vaccination centre exists. I
am not bashing France but given they’ve locked down 12m people in this region alone on the basis of public health emergency, there’s no sign of an emergency response. New big pharmacy near us says vaccine available from Monday and come and make an appt. I’ll go and see early next week. I’m feeling sad for the oldies with no internet etc
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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That’s terrible
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Quote: |
I’m feeling sad for the oldies with no internet etc
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Je ne comprends pas. This is the country that rolled out millons of Mintel terminals in the 1980s. Nevermind that "Oldies" are the big internet users.
Anyway I (as an oldie) looked it up on the Internet and France will be producing vaccines real soon now https://www.biopharma-reporter.com/Article/2021/02/10/France-ramps-up-COVID-19-vaccine-manufacturing I hope they don't experience the production problems other plants have experienced on start up.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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| ringingmaster wrote: |
| LaForet wrote: |
| @ski3 You're right, and it's based on what has happened before, in previous epidemics and pandemics. Prof. Whitty said early on that once you start a vaccination programme, then the race is on to complete it and get to the 75%+ herd immunity level. Because as the unvaccinated proportion diminishes, mutation increases. .... |
The herd immunity rate keeps being banded around at 75% (Good to see the + on your number). That is incorrect for COVID.
You hear a lot about the R rate or Reproduction rate - a measure of how many people each carrier infects. For the pandemic to shrink we know R needs to be below 1.0 .
There is also an R0 rate that is the natural R rate of the virus in the absence of any community measures like social distancing. For reference, Flu R0=1.6 and COVID R0=4.0 with the Kent variant being around R0=5.5. So from this it is clear that COVID is 3 to 4 times more infectious than Flu.
Each measure put into place will reduce R by a set amount. That can be closing pubs, shops or schools, or using masks & hand gel. In addition to stopping vulnerable groups getting sick and dying, the vaccine also has an effect on R – hopefully quite a big effect.
Herd immunity is achieved when the percent of people unable to transmit the virus is greater than the R0 rate. The math around herd immunity is simple but I have been explicit about the brackets so no one has to think about precedence rules.
Herd Immunity Threshold = 1 - ((1/R0) * Vaccine transmission prevention percent)
So given...
R0 = 4
Vaccine transmission prevention = Preventing 75% of transmission
1 - ((1/4) * .75) = 81.25%
So you need to vaccinate 81.25% to gain herd immunity
Now, given the Kent variant is estimated at
R0 = 5.5
Vaccine transmission prevention = Preventing 75% of transmission
1 - ((1/5.5) * .75) = 86.36%
So you need to vaccinate 86.36% to gain herd immunity
And that is higher than most vaccination campaigns achieve.
Either we get to that 86.36% level, or we will all have to maintain community measures like mask wearing or occasional lockdowns indefinitely . (This takes no account of the amount of the population that get short term immunity from getting COVID) |
Thanks for that - very useful.
I'm not sure I agree with your conclusion though.
Say we get 75% vaccination rate with it skewed to the vulnerable (mainly age but also other factors) then won't it be likely that we can just accept the unvaccinated getting infected because the fatality rate and hospitalisation rate will be manageable for society? Gradually the unvaccinated 25% will develop antibodies the natural way but this won't require population wide lockdowns?
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Oh and I presume that if 75% of the population are vaccinated this has a big impact on the R rate - not just because they don't infect others as much (your 75% prevention) but because it is harder for transmitters to come into contact with potential recipients? This means that control measures can be less severe?
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You know it makes sense.
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@jedster, Yes, this is just the math and mechanics, and my conclusion does state:
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"(This takes no account of the amount of the population that get short term immunity from getting COVID)"
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Yes, getting 75% of population vaccinated does have a reasonable effect on R. It is quite simple to turn the equation around to calculate the effect on R for a certain percentage of vaccination
Effect on R = - (Vaccine transmission prevention percent/(Vaccine given percent - 1))
So for the Kent Variant:
25% vaccinated, it drops R by 1.0 , leaving R4.5 by other means
50% vaccinated, it drops R by 1.5 , leaving R4.0 by other means
75% vaccinated, it drops R by 3.0 , leaving R2.5 by other means
80% vaccinated, it drops R by 3.75 , leaving R1.75 by other means
85% vaccinated, it drops R by 5.0 , leaving R1.0 by other means
86% vaccinated, it drops R by 5.35 , leaving R0.15 by other means
87% vaccinated, it drops R by 5.76 , leaving R-0.26 by other means
So you can see that you don't get much bang for your first 50%, but it accelerates markedly after that
If you recall, Israel saw exactly that effect when they opened up after about 50% vaccine, and cases were rising again. Then the rise was rapidly smothered as they approached 70%.
I have made no value judgement regarding what policies are pursued, whether herd immunity is an achievable goal, Etc. Just thought the math interesting.
Last edited by You know it makes sense. on Mon 22-03-21 13:09; edited 1 time in total
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| under a new name wrote: |
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As we all know, they desparately responded ... and by restricting recreational outings to 1km from home max.
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@Tristero, I don't know which bit of France you're living in but that certainly was not the case here (Haute Savoie) ... there have been no distance limitations since early December ... |
It was in Serre Che. Don't take it from me. Just read what Mr. Weathercam wrote himself.
That's not even the main point though...
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Poster: A snowHead
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| VolklAttivaS5 wrote: |
What I don’t understand about France is the lack of urgency. A fair amount of their income comes from tourism both in summer and winter, a lot more than here presumably? But they don’t seem to be bricking it, it’s like they don’t really care about people’s businesses being affected?
Maybe I’m wrong but that’s the impression I’ve got, they aren’t fussed. |
You're wrong. Point is they just don't have enough vaccine.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| ringingmaster wrote: |
@jedster, Yes, this is just the math and mechanics, and my conclusion does state:
| Quote: |
"(This takes no account of the amount of the population that get short term immunity from getting COVID)"
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Yes, getting 75% of population vaccinated does have a reasonable effect on R. It is quite simple to turn the equation around to calculate the effect on R for a certain percentage of vaccination
Effect on R = - (Vaccine transmission prevention percent/(Vaccine given percent - 1))
So for the Kent Variant:
25% vaccinated, it drops R by 1.0 , leaving R4.5 by other means
50% vaccinated, it drops R by 1.5 , leaving R4.0 by other means
75% vaccinated, it drops R by 3.0 , leaving R2.5 by other means
80% vaccinated, it drops R by 3.75 , leaving R1.75 by other means
85% vaccinated, it drops R by 5.0 , leaving R1.0 by other means
86% vaccinated, it drops R by 5.35 , leaving R1.0 by other means
87% vaccinated, it drops R by 5.76 , leaving R-0.26 by other means
So you can see that you don't get much bang for your first 50%, but it accelerates markedly after that
If you recall, Israel saw exactly that effect when they opened up after about 50% vaccine, and cases were rising again. Then the rise was rapidly smothered as they approached 70%.
I have made no value judgement regarding what policies are pursued, whether herd immunity is an achievable goal, Etc. Just thought the math interesting. |
Your R value for 86% vaccinated is the same as for 85% vaccinated.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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@ringingmaster, my envelope (back of) came up with slightly different results than your equation approach - have I missed something?
Take 50% vaccinated (approx where we are now) with a vaccine 75% effective (your assumption above). Thus 0.75 * 0.5 of the population won't be available for infection, leaving 62.5% of the population vulnerable. So with R0 of 5.5, instead of one person infecting 5.5 others they will infect 5.5 * 0.625. R has dropped to slightly more than 3.4, not to 4.0 as in your table.
Either way it leaves a lot of heavy lifting for lockdown restrictions to do for cases to continue to fall. But the question is how much that matters if it leads to a 99% reduction in serious disease, given that at any point new variants could change the maths.
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You need to Login to know who's really who.
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@Alastair Pink, Thanks - Cut and paste error. Corrected
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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@j b,
As a sidebar, we are no where near 50% at the moment. It takes 3 weeks to get some protection, so we have protection for those vaccinated on 28th Feb or earlier. That is ~20,000,000 out of 67,000,000, so around 29%.
The math I have presented above is the generally accepted way of modeling that relationship.
What you are not taking into account is that the chain breaking nature of the vaccine means that you can happily have a lot of unprotected people in islands of protection, who pose no risk of transmission of receiver. So the relationship between protection % and R is non-linear. It is actually a reciprocal, with a constant offset of 1.
By your approach, when we get to 100% coverage we will still have 25% of R remaining = 1.4. If you took your approach for something measles where R = 12–18, we would be in a permanent measles epidemic.
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maths
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| ringingmaster wrote: |
| By your approach, when we get to 100% coverage we will still have 25% of R remaining = 1.4. |
I think that is right. Herd immunity needs vaccination to completely (or close to) prevent infection if R0 is high, and the present vaccines don't do that. As I said above, the obsession with herd immunity is an unhelpful distraction.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| j b wrote: |
| ringingmaster wrote: |
| By your approach, when we get to 100% coverage we will still have 25% of R remaining = 1.4. |
I think that is right. Herd immunity needs vaccination to completely (or close to) prevent infection if R0 is high, and the present vaccines don't do that. As I said above, the obsession with herd immunity is an unhelpful distraction. |
I agree re the herd immunity distraction. The best case scenario is that we end up in a 'flu' type situation where folks are vaccinated annually against the prevailing covid strain and that enough people are vaccinated to prevent excess covid deaths as a consequence of this. Folks will continue to catch covid - as we all do with the cold and flu - but hopefully wont die of it - but a small proportion always will despite vaccination.
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| j b wrote: |
| ringingmaster wrote: |
| By your approach, when we get to 100% coverage we will still have 25% of R remaining = 1.4. |
I think that is right. Herd immunity needs vaccination to completely (or close to) prevent infection if R0 is high, and the present vaccines don't do that. As I said above, the obsession with herd immunity is an unhelpful distraction. |
Not sure what to say other than, no it does not.
The math is outlined above. Plenty of academic papers on the subject if you want to dig deeper.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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@ringingmaster, I don't want to criticise your math (or maths) but isn't 100% coverage with a vaccine that is 75% effective at stopping infection the same as 75% coverage with a completely efficient vaccine? Neither would be able to generate herd immunity for an infective agent with R0>4.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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@j b, I think the point is that those who get infected will also get antibodies so will add to the count of those with antibodies due to vaccination, so in theory herd immunity should be reached one way or another.
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Along with a few thousand extra deaths along the way, as waiting for herd immunity will undoubtedly take longer than vaccination.
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You know it makes sense.
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@MorningGory, true there will be those with natural antibodies which changes the calculation a bit. But that sits outside being a strategy that public health can organise to put in place at speed.
(And some of the same questions apply, e.g. how good is a natural immune response at stopping a second infection? and across different variants? I still think herd immunity is not a practical strategy at this stage).
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Herd Immunity is the 'practical strategy' surely? It's why you vaccinate. Being the %point at which enough people are immunised - or immune through having ben infected and survived - for any outbreak in the un-immunised to be contained. It varies by disease and circumstances (each disease has it's own profile). Natural immune responses are not the best way to get to herd immunity, because basically, most of the population has to contract the disease, which is not great if the death rate is high. And even if the death rate isn't high, the impact on healthcare of a lot of people needing hospitalisation can still be catastrophic.
We were told early on that once you embark on a vaccination programme then 'the race is on' to get to the herd immunity target %, and it's absolutely critical you do so. Because as you immunise, the dwindling target population for infections prompts higher levels of mutation within the un-immunised. It's a bit either/or - either you go with natural immunity and take a leisurely stroll through a pandemic, suffering the consequences or you blast through a vaccination programme ASAP and hope to get to herd immunity before any serious mutations arise.
This is why the likes of the CRG's 'let's protect the vulnerable and leave the rest to get back to normal' idea is so very bad. Because it's based on a false, non-scientific premis: that there is no such thing as herd immunity - and dispensing with key public health countermeasures before you hit herd immunity is the very worst thing to do. No one is saying we should maintain 100% lockdown, but the dilemma is to choose the right restrictions to lift progressively. Having immunised the over-65s is not the end of the road.
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Poster: A snowHead
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@LaForet, I agree with all of the above, except ...
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Because as you immunise, the dwindling target population for infections prompts higher levels of mutation within the un-immunised.
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I'm not sure that makes sense, does it? AIUI, the greater the pool of infections, the more likelihood of mutations. I don't think viruses are bright enough to mutate in response to a dwindling target population. AFAIK viruses mutate simply through copying errors, with some errors making them worse and some better.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| LaForet wrote: |
We were told early on that once you embark on a vaccination programme then 'the race is on' to get to the herd immunity target %, and it's absolutely critical you do so. Because as you immunise, the dwindling target population for infections prompts higher levels of mutation within the un-immunised.. |
I think (from my Twitter reading) that that’s not quite right - the virus doesn’t mutate more because of vaccination, because mutations are random. But the slower you go, the more opportunities it has to mutate, so the chance of a “vaccine busting” mutation occuring increase because there are more infections - it’s not the vaccination programme that causes mutation, they always happen. The Kent variant is massively dominant pretty much anywhere it appears because of its transmissibility, but vaccines appear to stop it dead by preventing infection, so the worry is that something else could become dominant instead. The SA one they’re all getting excited about appears from the small and (crucially) short trial in SA to be less affected by AZ in preventing mild disease - however some encouraging news on the J&J vax suggests it does prevent infection but after 28 days + - the SA trial was on people 14 days after vax, and the technology is apparently similar for AZ and J&J, so it may be that AZ will be effective after a longer period.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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From my reading, all current vaccines work against the SA variants, just a few % lower efficacy. It is not a binary work/don't work situation. But critically they still keep you 100% out of hospital. So you are a bit more likely to get sniffy, but still won't get seriously ill. The Third Wave now sweeping Europe seems to be caused by the same variant which caused ours in November-February (a.k.a Kent) and vaccines work just as well against it, so I am a bit confused when Boris talks about the European wave washing up on our shores when we've already had it.
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You need to Login to know who's really who.
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| LaForet wrote: |
| Herd Immunity ... It's why you vaccinate. |
No, or at least not always. The aim with measles is herd immunity, but recently it has struggled to achieve that reliably; the aim with flu is to stop serious disease in vulnerable populations.
In the case of measles it has been possible to make a vaccine that can be given once in childhood to provide lifelong protection, and which effectively blocks a person getting the infection at all let alone passing it on. Those conditions are not met by flu vaccines, and as far as we can tell they are not being met by Covid vaccines.
(With Covid vaccines, so far it has been possible for vaccinated people to get mild infection and thus transmit to others. And we don't know for how long protection lasts. But it is conceivable that with time, and most likely second-generation technology, it will prove possible to have a vaccine that makes herd immunity an achievable aim).
FZ and Andy - I agree that decreasing numbers of infections mean mutations will happen less often. Though that is an effect that will only be meaningful at global, rather than national, level. What vaccination does is create a huge natural selection advantage for a mutation that evaded protection, and would thus have a big pool of people to spread among. But such a mutation is not very likely and will become much less likely as the number of infections comes down.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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I'm going to ask an admin to hoover all this into another thread. It's got nothing specifically to do with lockdown in France.
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What I said is what my understanding of the Briefings were, but I could be wrong, obviously. But it was that the reduction in the target infection pool size forces higher levels of mutation. Why this happens wasn't explained in detail. I can conjecture why, but I'm not an epidemiologist.
You're right that mutation is a fault in the DNA copying process, as gzillions of virus in your body replicate: and every so often, there's a fault in the copying, and we're unlucky if the fault is beneficial to transmissibility and/or means worse symptoms. But the mutation rate isn't constant and can be increased by external factors. Plus the rate of infection can also increase because of external factors and this produce more replication events, and thus more mutations. I don't know the why, but the statements (as I understood them) were that it's only when you're beyond the herd immunity % for the virus in question that will you fully constrain further outbreaks.
You're also right that the virus isn't sentient - it's more like a Backbench MP  (inasmuch as it's got a fixed response to stimulus and no ability to think strategically. It just does what it does.)
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@Claud_B It has everything to do with Lockdown in France. This is the science that underpins whether France will descend into further, repeated waves of infections and at worst, a new variant that's immune to current vaccines - and end up in a state of Social Chaos that to match a post-apocalyptic drama. Or not. Which seems pretty much on-topic for the thread title.
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I disagree. It has everything to do with that anywhere. Not specifically in France. In fact there has been far more said about UK, 50% vaccinated etc, than France.
I maintain that is is better placed in a standalone thread. Admins can decide.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| Quote: |
I don't think viruses are bright enough to mutate in response to a dwindling target population.
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Exactly. They are not. Not connected and not intelligent. Just to amplify, suggesting that greater levels of population immunity put great pressure on virion mutation suggests connections that don't exist. Virion B does not know that virion A has encountered an immune individual. Unless I am missing something?
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@under a new name, I thought if you were infected with a virus it emailed everyone in your address book? Surely that's how they'll know
I'll get my coat
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FAQ
