Naked Science Forum
Life Sciences => Physiology & Medicine => COVID-19 => Topic started by: vhfpmr on 24/05/2021 13:25:27
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So can the vaccine give us herd immunity if enough of the population have it, or will the virus continue to circulate anyway until a vaccine-resistant mutant emerges?
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Yes and yes, because herd immunity isn't the same as inherent tolerance or immunity. If 80% of the population is immune through vaccination or prior infection, the probability of anyone else being infected becomes very small (herd immunity) but those that are infected can indeed breed mutants.
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The point I was leading to really is that if you can achieve herd immunity by a sufficient margin, any outbreak will quickly die out, so the risk of a resistant mutant emerging is significantly reduced. The anti vaxxers are arguing that there's no point in them being pressurised into getting vaccinated, because it's only themselves they're putting at risk.
The fewer there are vaccinated, the quicker there will be a resistant strain, and the higher the risk that this will occur faster than we can develop and administer new vaccines.
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The anti vaxxers are arguing that there's no point in them being pressurised into getting vaccinated, because it's only themselves they're putting at risk.
If that were true, they wouldn't be shunned by intelligent people or loathed by those they infect.
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Yes, we could get to herd immunity, if enough people are vaccinated (including children).
But you seem to be talking about elimination.
- Elimination is much harder, and it's only worthwhile if the disease causes an ongoing severe health burden, and doesn't have an animal reservoir.
- We know several other species can catch COVID-19 (including house cats and mink), so it will be harder to eliminate entirely.
- It is possible that when the children who caught it as a child get old, it won't be any worse than the common cold, and it will just become endemic (like several other coronaviruses which we group under "the common cold"). That means it doesn't pose an ongoing burden of disease.
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Doesn't it seem obvious, that the main objection to the term "herd immunity" comes from the word "herd".
This word evokes ideas of a "herd" of cattle. And so makes people think they're being treated like cattle.
Which is bound to arouse feelings of offence, resentment and indignation.
Suppose instead a more agreeable term had been used. Such as "population immunity". Or "public immunity"
Would that have been accepted, as a concept, and so perhaps, have avoided the lock-downs?
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We are already seeing case numbers plunging in the USA and much of Europe.
I still believe the disease will become a seasonal disease, and while we did get cases last summer, they weren't as many as last fall.
What we don't know is whether the case numbers will drop to essentially zero over the summer as often happens with the flu/influenza, or if we'll see numbers continually trickling in.
I am still hoping for a multivalent booster vaccine to be available this fall to help us get through the coming winter.
The problem will be whether we will get the vaccine distributed broadly enough to the third world which has been struggling to get the doses to prevent a fall resurgence of a vaccine resistant strain.
There would be a pretty extreme benefit to the richer countries to give a way a few billion doses of the vaccine to the poorer nations, and knock this thing down once and for all.
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I will say that a Flu/Influenza free winter was quite something.
We can't do everything we did this year to control COVID every year, but there would be global benefits of broadly distributing the Flu vaccine with the COVID vaccine. And also pounding on Polio.
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Would (calling it "population immunity" or "public immunity") have been accepted, as a concept, and so perhaps, have avoided the lock-downs?
Calling herd immunity a different name would not have:
- Made the virus any less infectious
- Reduced the number of people who got infected (in the absence of a vaccine)
- Reduced the number of fatalities
- Reduced the need for social distancing, face masks or lockdowns.
What might have helped the UK is if, instead of seizing on "herd immunity" as an excuse to go about your normal business, they had:
- Observed that they would not get herd immunity until most people had been vaccinated
- Observed that getting a new vaccine approved would optimistically take 6-9 months, and at least 6 months to roll out to a significant fraction of the population
- And declared that, in the meantime, there would be border quarantine, contact tracing and compulsory mask-wearing
That might have reduced lockdowns (but not prevented them)
Even New Zealand, with some of the most effective quarantine restrictions in the world, has had several short lockdowns, and they are thousands of kilometers from their nearest neighbours (most of whom also have low levels of COVID-19).
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What we don't know is whether the case numbers will drop to essentially zero over the summer
Doesn't seem to be the case in India. The virus inhabits 37°C thermostats and really doesn't know what the weather is like outside. Whether it prospers depends entirely on how those thermostats interact.
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If the herd isolated at home for 3 weeks at at time, it would be immune.
If every member of the herd was vaccinated with one of the fairly effective vaccines we have, that would also produce herd immunity.
Another way to do it would be to remove all restrictions and let the virus run riot.
After a while we would have a "survivor population" with herd immunity.
So far, we don't seem to have done any of those properly.
Round here, we got worryingly close to the third option- which is the one with the highest death rate- and have decided against the first two. But that's because people voted for Boris,
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Two different interpretations of herd immunity.
I would distinguish between the survivor population as a herd of immunes, i.e. a subspecies with inherent and hertiable immunity or tolerance, and a population of "normals" who have simply survived but do not possess heritable immunity.
Problem is that the wild carriers of COVID seem to be in the first category, and human survivors mostly in the second, larger but much less robust category. So as long as there is a wild pool of infection, we need to retain active protection.
Allowing the lazy journalese of "voted for Boris", I wonder if "voting for Jeremy" would have been any better. The Labour Party under JC couldn't agree to implement the result of a referendum without having another one, and the man himself, having campaigned to put his finger on the nuclear button, couldn't say whether he would press it or scrap it. Faced with a COVID epidemic, I'm sure the front bench would still be arguing about whether it was inherently discriminatory, was it permissible to suggest it originated in a socialist utopia, or should known terrorists be vaccinated before appearing on a public platform with The Leader. The choice seems to be between corrupt incompetence and prejudiced indecisiveness.
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Look, just replace the unfortunate phrase "herd immunity" by "communal immunity", and all cattle-based negative reactions will vanish. It's just a matter of getting the words right.
Aren't there many examples of this in human history?
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My comment still stands, whatever you call it.
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It's just a matter of getting the words right.
No, it's not.
The problem with "herd immunity" isn't the use of a word commonly used for animals.
The problem with herd immunity is the massive death toll if you try to do it without a vaccine- as Boris was planning to do.
Changing the name doesn't save any lives.
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The Labour Party under JC couldn't agree to implement the result of a referendum without having another one,
Which was the only sensible policy, given that the will of the people had shifted in the mean time.
https://en.wikipedia.org/wiki/Opinion_polling_on_the_United_Kingdom%27s_membership_of_the_European_Union_(2016%E2%80%932020)#/media/File:Brexit_post-referendum_polling_-_Right-Wrong.svg
What would you have done?
Would you have acted like Boris and been a dictator leading the population down a path which you knew was the wrong one, or asked if they were sure?
and the man himself, having campaigned to put his finger on the nuclear button, couldn't say whether he would press it or scrap it
It's usually considered sensible not to announce your military strategy to your enemies in advance.
So, your major complaints seem to be that he acted sensibly.
How very upsetting for you.
But it does suggest that he might have acted sensibly as PM rather than, for example, going round a hospital in a pandemic, shaking hands with patients, and then bragging about it.
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It's just a matter of getting the words right.
No, it's not.
The problem with "herd immunity" isn't the use of a word commonly used for animals.
The problem with herd immunity is the massive death toll if you try to do it without a vaccine- as Boris was planning to do.
Changing the name doesn't save any lives.
The question of whether more lives would've been saved by letting the Covid virus run its natural course, instead of desperately trying to fend it off by inventing vaccines and locking down entire countries, will only be answered in the future.
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The question of whether more lives would've been saved by letting the Covid virus run its natural course, instead of desperately trying to fend it off by inventing vaccines and locking down entire countries, will only be answered in the future.
No.
Letting the virus run riot would kill essentially all the susceptible people.
Any policy which saves any of them is better.
Of course, in the long run, everybody dies, so it's a meaningless way to look at it..
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The question of whether more lives would've been saved by letting the Covid virus run its natural course, instead of desperately trying to fend it off by inventing vaccines and locking down entire countries, will only be answered in the future.
No.
Letting the virus run riot would kill essentially all the susceptible people.
Any policy which saves any of them is better.
Of course, in the long run, everybody dies, so it's a meaningless way to look at it..
Isn't that exactly what Boris thought - Why inflict suffering on living people by imposing "lockdowns"? It's meaningless. Because in the long run, as you say, all the people will end up dead anyway.
I think you and Boris are in scientific tune, but you don't like him because he's a Tory. Isn't that a correct analysis?
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It's meaningless. Because in the long run, as you say, all the people will end up dead anyway.
Drop dead.
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Not a Subject Matter Expert...Still!
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Excessive use of medications & steroids are already causing complications such as mucormycosis.
Black fungus, White fungus, shot up diabetes, increased heart attacks, brain fog etc etc.
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Lockdowns & Quarantines bring about a painful financial crunch, Not to mention increased Depression & mental illnesses.
Less money, less purchasing power to buy medicines, & stress levels paramount.
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Third World Countries might Not be capable of manufacturing or even buying Vaxx.
Even if billions of Vaxx are Donated, orthodox, religious extremists, illeterate, nincompoop populations Might Deny getting Vaxx.
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Do Not have a clue, as to how long Antibodies are present & sustained within.
Have heard of folks getting infected Thrice.
Even Two dosed Vaxx are susceptible to a mild infection.
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The more it Spreads, the More chances of Mutations & Variants.
Cannot say if a New strain might emerge that renders Vaccines Ineffective.
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Do Not know if this can combine with Ebola, Rabies or HIV and become a Double Whammy.
No Clue on how it might be brought under control after other species start getting infected.
P.S. - Pandora's Jar!
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the survivor population as a herd of immunes, i.e. a subspecies with inherent and hertiable immunity or tolerance
When smallpox was introduced to the (previously unexposed) Australian Aborigines, the death rate was reportedly around 90%. The succeeding generations were apparently better able to survive this pathogen.
- That is a high price to pay for a tolerant community
- But it won't work for COVID-19, since most of the fatalities are past childbearing age
The problem is that a human generation is 25-30 years
- while a COVID-19 generation is 1 week, with new mutations spawned every 2 weeks.
- So the virus can always adapt faster than we can
Vaccination is a way to achieve community protection, but without the heavy death toll.
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What would you have done?
Would you have acted like Boris and been a dictator leading the population down a path which you knew was the wrong one, or asked if they were sure?
Obviously I would have had a referendum every six months to see if they still felt the same way as last time. Isn't that what the SNP wants to do? And it is consistent with the European Union's insistence that the Irish should continue to vote until they came up with the right answer.
However, reading your reference, I infer that you would prefer not to actually ask everyone's opinion in a full referendum but to impose the majority will of the 1000 people you selected, on everyone else. Clearly an admirer of the classics, including the Greek definition of democracy.
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The question of whether more lives would've been saved by letting the Covid virus run its natural course, instead of desperately trying to fend it off by inventing vaccines and locking down entire countries, will only be answered in the future.
No, we can answer it now.
We know that
COVID kills about 4% of all those it infects
homo sapiens has no inherent immunity
there is no external vector
so eventually everyone will be infected if it "runs its natural course".
Therefore if we did nothing, of the 67,000,000 UK citizens alive in 2020 about 2,700,000 would eventually die from an entirely preventable disease, and if nobody can be reinfected, a further 10,000 would die similarly in every subsequent year. However it seems that reinfection is possible so the more likely number is at least 100,000 per year for ever.
Thanks to governmental incompetence, about 128,000 have died, and thanks to lockdowns and vaccination, the number is unlikely to exceed 150,000 by the end of 2021 with an ongoing toll of about 100 per year.
Had the government acted as sensibly as that of New Zealand the total would have been about 350 deaths to date with no significant ongoing burden of disease in future. That's what a socialist government can do if it stops playing internal politics and gets on with the job.
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Excessive use of medications & steroids are already causing complications such as mucormycosis.
Black fungus, White fungus, shot up diabetes, increased heart attacks, brain fog etc etc.
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And an increase of life expectancy of 85 days per year since 1930, leading to an increase in the diseases of old age such as those you have listed.
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Obviously I would have had a referendum every six months to see if they still felt the same way as last time.
That's a fine idea, and then, when you find that the outcome has settled down to a consensus of sorts, you can use that as the basis for action rather than pretending that an advisory referendum was legally binding like the Tories did.
You might even avoid driving a coach and horses through the fundamental point of democracy.
I infer that you would prefer not to actually ask everyone's opinion in a full referendum but to impose the majority will of the 1000 people you selected, on everyone else.
I say that having a full referendum would be a good thing, and you infer from that that I don't want the decision made by referendum.
Had you been drinking or something?
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That's a fine idea, and then, when you find that the outcome has settled down to a consensus of sorts,
And how would you define a consensus, other than 51% agreeing with you? I'd rather be drunk than talk like a politician!
I looked at the opinion polls you referred to. The sample size was between 1000 and 2500 with one outlier at 10,000. I would have thought that a 72% sample of a 30,000 000 electorate would be a better indication of consensus.
The 1975 "stay" referendum expressed significant support for EC membership, with 67% in favour on a national turnout of 64%. The referendum result was not legally binding....
So support for the status quo (which is all the 1975 referendum was about - the UK had entered the EEC two years earlier) had steadily fallen to the point of "leave" as the trade deficit grew, there was no indication of any improvement on the terms that Cameron had negotiated, and the initial referendum wasn't binding anyway.
The engine is on fire, you have failed to put it out, you were not legally bound to fly it anyway, and the plane is spinning towards the sea. When do you eject?
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And how would you define a consensus, other than 51% agreeing with you? I'd rather be drunk than talk like a politician!
So , you wanted to announce that you don't understand what "settled down" meant.
OK that's fine.
I would have thought that a 72% sample of a 30,000 000 electorate would be a better indication of consensus.
Yes, statistically better.
But you seem to be refusing to consider the obvious.
People have hanged their minds since they discovered that the brexit dividend was a lie.
As accurate a poll as you could do ten years ago would tell you next to nothing about today's view on something.
The fact remains that the opinion of the people, at the time the UK left the EU was that leaving was a mistake.
Nothing which has happened since then will have altered that view.
The engine is on fire
No it isn't.
A man who is trying to sell you a fire extinguisher (at a huge price) is telling you that the engine is on fire, but in reality it is working fine. (Also, the fire extinguisher doesn't actually work).
Don't you think you should ask the passengers to look out of the window to check, before you give the order to ditch?
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The fact remains that the opinion of the people, at the time the UK left the EU was that leaving was a mistake.
Not according to your source, which shows that the opinion of 1 - 2000 people swung on various dates between plus 8 and minus 10 percent lead, with a consistent 12 - 13% "don't know". If you take the known phenomenon of "buyer's regret" into consideration, the result is at best meaningless and at worst demonstrates the government's incompetence at negotiating with a bunch of leeches - something you should never do!
The steady increase in trade deficit with the rest of the EU had been charted by the government's official statisticians for 50 years, regardless of the color of government or the will of the people. Only a fool listens to politicians: a wise man reads the company accounts.
If the UK was a net beneficiary of the EU, why did they make it so difficult for us to leave?
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If the herd isolated at home for 3 weeks at at time, it would be immune.
Isolation would interrupt transmission, but wouldn't provide immunity. So re-infect, and the infection can go wild.
That is one of the reasons I believe my state has been struggling. It has had some of the lowest case numbers throughout he first year, but that left a lot of people still vulnerable coming into the second year.
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why did they make it so difficult for us to leave?
In what way did they do so?
Not according to your source, which shows that the opinion of 1 - 2000 people swung on various dates between plus 8 and minus 10 percent lead,
There's about 70 polls on the right hand half of side of that graph.
If the UK was uncertain about it then, half the time, the red dot would be on top, and had the time the green dot would be on top.
What you are saying is that they tossed a coin 70 times and got 69 heads- but you still think the coin is unbiassed.
That's something like a 1 in 10^19 chance.
Feel free to cling to it, but don't expect many followers.
BTW, if a passing mod would like to take this and dump it somewhere less off topic, that would probably be good.
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and the infection can go wild.
No it can't- because everyone is isolating.
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If the UK was uncertain
What statistical test suggests that 1000 people is an efficient sample of 30,000,000?
If you are trying to discriminate a 2% difference with P = 0.05 you need about 20,000 samples.
But to return to Clifford's statement: no, if everyone isolates for 3 weeks nobody will be immune but the disease will die out in that group. Elimination is a 3-stage process: immediate quarantine minimises the number of incoming carriers, rigid isolation prevents the disease from spreading among your population, then you vaccinate them to prevent it entering from outside when you lift the quarantine. Any other approach just destroys the economy and kills people.
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What statistical test suggests that 1000 people is an efficient sample of 30,000,000?
https://en.wikipedia.org/wiki/Opinion_poll#Margin_of_error_due_to_sampling
But you still have to explain your view that in 69 out of 70 polls, most people didn't say it was the right choice, but that doesn't mean that most people don't think it was the right choice.
If you are trying to discriminate a 2% difference
We aren't.
The margin is bigger than that.
And, that means that a smaller number of people will suffice.
If you really cared, you would have clicked on the link to the poll and found this
"All polls are subject to a wide range of potential sources of error. On the basis of the historical
record of the polls at recent general elections, there is a 9 in 10 chance that the true value of a
party’s support lies within 4 points of the estimates provided by this poll, and a 2 in 3 chance
that they lie within 2 points"
But the fact remains that when 69 out of 70 say the same thing, either you need to show serious bias or you accept the answer.
Or, if you are a brexit supporter you stick your fingers in your ears and say "La la la; I;m not listening"
This technique also allows you to say that a 23% fall in trade isn't a problem.
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If you are losing money in your trading, a 23% fall in trade is a very good thing.
If we play poker twice week and you lose very time, would you prefer to play three times a week or once? OK, you are a gambling addict, but what does your bank manager think?
Anyway, to return to the subject, thanks to the sustained commercial brilliance of the European Union in negotiating vaccine contracts, our neighbors will probably be going for the herd immunity option, so let's wait and see.
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A friend of mine at uni used to play poker and lose heavily.
He knew this and kept on playing.His parents were rich so the losses were inconsequential to him, but he made sure his mates had enough beer money.
And that meant that he had someone to have a beer with- which was valuable to him. The thing about trade is that the items have different values to the person buying and the person selling.
If you look at the "balance of payments" and nothing else you get the wrong impression.
You already lost this argument when I pointed out that I give the supermarket much more money that it gives me.
(At the time, I think the example I used was the pub, so it must have been over a year ago that I explained why you are wrong to only look at one side of the equation).
My employers "balance of payments" looks even worse. They give money to lots of people.
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My employers "balance of payments" looks even worse. They give money to lots of people.
...and never invoice anyone? Even if you work in a benefits office, somewhere there is a tax collector or charity chugger bringing in the cash, and if you spend more than you collect, the office will close.
Just to recap a simple argument. UK-EU trade consists of two elements: import and export. Most businesses do one or the other, and make a profit by doing it. Clearly if you do more business of either sort, you make more profit. So removing trade tariffs is good for business. But if the net imports to a country exceeds the net exports, the country is exporting money, and in the case of the EU, the taxpayer was paying a membership fee for the privilege of doing so. Good for business, bad for Britain.
If you consider yourself as the poker player, I'm glad I'm not your parent. Friends that you have to buy (or rent - beer doesn't last long) are not good friends.
Old adage: if you do business with friends, you will end up with no friends or no business. By all means establish a federal Europe with one langhuage, a single system of statute law and citizenship, but a bent trade agreement, an incompetent and unaccountable bureaucracy, and a parliament with no power, is not worth my tax money.
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...and never invoice anyone?
The point is that they don't invoice me; they pay me.
Friends that you have to buy
It's interesting that you have assumed he "had to" do this, rather than chose to.
Good for business, bad for Britain.
Where does Britain get it's wealth from?
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Are the vaccines going to be good enough?
From Wiki, covid R0 is 2.4 - 3.4, so if the Δ variant is reportedly 64% more infectious
R0Δ = 3.9 - 5.6,
and the herd threshold 1-1/R = 75% - 82%
If Pfizer is 87% efficient against Δ then we need 86% - 94% vaccinated, but
OAZ is reportedly 60% efficient against Δ, so we would need more than 125% of the population vaccinated.
And that's without excluding children and refuseniks.
A year ago John Edmunds said that all epidemics end with herd immunity (natural or vaccine), but what happens with flu? That fizzles out each year without seemingly getting anywhere near herd immunity.
https://www.gov.uk/government/news/vaccines-highly-effective-against-b-1-617-2-variant-after-2-doses
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what happens with flu?
It changes every year.
So we do achieve herd immunity to one year's version, but it's not much use next year.
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we would need more than 125% of the population vaccinated.
And that's without excluding children and refuseniks.
The existing vaccines are all designed to be effective against the original (Wuhan) variant*
- They are not so effective at preventing infection and transmission of the new variants, but they are still very effective at reducing the death rate, transmission and probably the incidence of long COVID (compared to unvaccinated people) - so that's a win!
- Reducing circulation in the worldwide community is essential to reducing the number of new variants popping up
- While the vaccine makers work on their vaccine 2.0 that will deal with the newer variants.
If, with vaccination, we can make COVID-19 like the common cold, we won't need to vaccinate every year, as everyone will catch it as a child, before they get old enough to die from it
If, with vaccination, we can make COVID-19 like the flu, we can leave it to susceptible older individuals to get an annual booster, but the younger people may decide to "tough it out", on the basis that they will probably survive it.
*PS: Why isn't the original (Wuhan) variant called "Alpha", instead of the Kent variant?
- Maybe we should call it "ground zero"?
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*PS: Why isn't the original (Wuhan) variant called "Alpha", instead of the Kent variant?
Because it's the first change that gets called alpha.
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From Wiki, covid R0 is 2.4 - 3.4,
Surely R is the average number of people infected by one carrier. It isn't strictly a property of the disease but of the behavior of the population, which is why quarantine works: if no carrier makes contact with anyone one else, R = 0.
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Surely R is the average number of people infected by one carrier.
R is the average number of people infected by one carrier, R0 is the average number of people infected by one carrier in the absence of social distancing measures.
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So we do achieve herd immunity to one year's version
HIT for flu is 17% - 29%, if there were that many getting it each year I would have expected to have had the flu at least once myself. I'm 62, and never had (symptomatic) flu yet. I don't know how common that is, perhaps I'm just immune.
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While the vaccine makers work on their vaccine 2.0 that will deal with the newer variants.
I suppose what I'm driving at is can they roll out new vaccines faster than the virus rolls out new mutants? Evolution means that faster mutating variants will prevail.
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R is the average number of people infected by one carrier, R0 is the average number of people infected by one carrier in the absence of social distancing measures.
So it is entirely dependent on where you live and how you travel. The probability of a nomadic hunter infecting anyone other than his immediate family is negligible, whereas the sort of people who cram into tube trains twice a day and spend their evenings in sweaty clubs can infect dozens.
can they roll out new vaccines faster than the virus rolls out new mutants?
No. You can't hit a target without seeing it first! You might strike lucky with something that turns out to be as effective against Y as it was against its design target X, or you might come up with a "nuclear option" that alerts the body to every kind of invader without actually precipitating autoimmunity, but the chances of either are small. The enemy is mutating with every generation and in principle it only takes one survivor to kick off a whole new swarm of invaders and evaders.Positive prevention (quarantine) is the only guaranteed effective response.
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can they roll out new vaccines faster than the virus rolls out new mutants?
No, but they have a fairly effective system in place for influenza:
- A worldwide network monitoring for new flu strains*
- A tracking system which records the genetics & spread of new strains (which was reused for COVID tracking)
- A team of experts who predict what are likely to be the common variants in 6 months time (for the opposite hemisphere about to enter winter)
- A vaccine platform (chicken eggs) which can quickly pivot to manufacturing vaccines for these new variants
- A manufacturing and delivery system that can get vaccines into the arms of susceptible people before winter gets underway.
It's a fairly well-oiled machine; it's not always right, but at around 75% effectiveness, that reduces mortality by more than 75%.
- And especially if they insist on visitors to aged care homes being vaccinated (as happened around here, this year)
*I expect that the team monitoring for flu-like symptoms in Wuhan were alerted to an outbreak of a respiratory illness early in 2020. But as soon as they discovered that it wasn't flu, they decided it was just SEP (Someone Else's Problem) and ignored it.
See: https://en.wikipedia.org/wiki/Influenza_vaccine#Annual_reformulation
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R is the average number of people infected by one carrier, R0 is the average number of people infected by one carrier in the absence of social distancing measures.
So it is entirely dependent on where you live and how you travel. The probability of a nomadic hunter infecting anyone other than his immediate family is negligible, whereas the sort of people who cram into tube trains twice a day and spend their evenings in sweaty clubs can infect dozens.
It is, but that's not the point. The values of Ro I was quoting from Wikipedia are presumably population averages, and so are the calculations you need to do if you want to vaccinate a population. Nobody cares whether Mrs Jones infects Fred Bloggs (until it comes down to contact tracing), what's of interest is how many new infections you get on average from each 1000 infected. Since the majority of the population live in densely populated areas, the infection rate in those areas is going to be of more relevance and interest than the rate out in the sticks.
can they roll out new vaccines faster than the virus rolls out new mutants?
No. You can't hit a target without seeing it first! You might strike lucky with something that turns out to be as effective against Y as it was against its design target X, or you might come up with a "nuclear option" that alerts the body to every kind of invader without actually precipitating autoimmunity, but the chances of either are small. The enemy is mutating with every generation and in principle it only takes one survivor to kick off a whole new swarm of invaders and evaders.Positive prevention (quarantine) is the only guaranteed effective response.
That's not what I was getting at, it's obvious you can't prevent a disease that hasn't arisen yet, what I was wondering is if we'll get to a stage where we can't finish vaccinating everyone against one variant before the next arrives. Producing and administering a vaccine is going to take a year or so just in the first world, let alone the third world, and in that time, numerous mutants have already arisen, any one of which could have been resistant.
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they have a fairly effective system in place for influenza
But they were only vaccinating a tiny sector of the population for flu. At 62, I wasn't eligible for the flu vaccine until they lowered the age limit to 50 this year. Covid requires everybody to be done, and that's on top of doing the flu as well. There was a piece on the Radio 4 Today programme this morning covering the increasing unrest among GPs about the impending workload.
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what's of interest is how many new infections you get on average from each 1000 infected. Since the majority of the population live in densely populated areas, the infection rate in those areas is going to be of more relevance and interest than the rate out in the sticks.
And as we have seen repeatedly, R in any area is not simply a function of population density or infectivity, neither of which has changed in the UK until the delta variant arrived, but of human behavior. Strict quarantine prevents transmission, vaccination sometimes prevents infection of the recipients of what is transmitted. Quarantine can be applied rapidly and universally if you have a competent government, and is 100% effective in a few weeks, whereas vaccination requires development, testing, production,distribution and delivery, takes 18 months to cover 50% of the population, has all sorts of side effects and doesn't always work.
The problem is that we have a corrupt and incompetent government, so we have to put up with excess deaths, long COVID, and a permanently damaged economy, instead of a month's national holiday and effective border controls
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None of this is of any relevance to what I'm arguing. If you want a vaccine that will enable you to end quarantine and return to normal behaviour, then you need to do vaccine calculations using the R value that relates to normal behaviour, and not that which relates to quarantine conditions. We've already shown that we can get R below one using quarantine alone, the open question is whether can we get R below one using the vaccine alone.
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It's relatively easy to find out how well a vaccine prevents death.
You take a big group, vaccinate half of them, and then count the deaths in each group.
It's more difficult to measure the prevention of infection where many infections are asymptomatic.
You need to regularly re-test all the people in your survey.
It harder, but it's possible.
But it's difficult to measure the effectiveness of a vaccine in terms of how much it reduces spread, because, in general, we simply don't know who the virus was spread to and from.
So the only thing you can do is vaccinate essentially the whole population and see what happens to the measured value of R (and make the laughable assumption that nothing else has changed).
So, yes, it would be great to know if the vaccine can end the pandemic,
But the only way to find out is to vaccinate the population (or some acceptable subset) and see if it works.
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you need to do vaccine calculations using the R value that relates to normal behaviour,
Assume that reinfection is not possible, and that normal behavior depends on their being a negligible probability of being infected even if you take no special precautions.
If R < 1 then normality will prevail when a sufficient number have been infected, whether or not you vaccinate anyone.
If R > 1 you will reach that equilibrium quicker and with more casualties.
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If R < 1 then normality will prevail when a sufficient number have been infected, whether or not you vaccinate anyone
If you leave people to get infected without a vaccine, a lot more will die.
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Only about 4%, and mostly the elderly and infirm, as with any herd. The problem with COVID is that 20% of those infected require hospital treatment and half of those suffer longterm disability: this is more serous than death for the herd.