Covid-- exit strategies

[DB]

Brunei, St. Vincent Grenadines, Macao, New Caledonia, Grenada, Saint Kitts and Nevis, Greenland, Falklands, Anguilla & The Holy See. You can easily check it yourself on worldometers. Yes they are all small, however China appears to be only importing casesso is elimanated from the community. It has pretty much gone from Vietnam, Mongolia, Thailand, Cambodia, Laos, Malaysia.

So basically very small and/or remote countries, who won't be able to keep it out. Really not comparable with Europe, is it?

And you seriously believe stats coming out of China?

 

[Philip Elliott]

Herd immunity is where a sufficient proportion of the population has immunity, meaning that spread is relatively limited - as we have with lots of diseases. It doesn't mean that it's completely gone away. As pointed out many times, the only formerly widespread human virus which was eradicated is Smallpox, and that took close to 200 years from the first vaccine for it.

Go on....tell us which diseases we have acquired herd immunity naturally for...

Meanwhile, recent research has shown that smallpox were first appeared in 8th/9th century Scandanavia and was spread by the Viking raids. Those who survived had lifelong immunity yet it became the deadliest disease in history and was still killing millions until mass vaccination was introduced - absolutely no sign of natural herd immunity there. A commercially created vaccine didn’t appear until the late 19th century and a global campaign for eradiction began in 1958 so eradication happened a lot quicker than you think. The Polio vaccine was invented in 1950 and it is now eliminated from every continent except Asia and then it is mainly Pakistan.

== Doublepost prevention - post automatically merged: 20 Sep 2020 ==

So basically very small and/or remote countries, who won't be able to keep it out. Really not comparable with Europe, is it?

And you seriously believe stats coming out of China?

You think they are hiding outbreaks despite being open about the Beijing outbreak and went back added more deaths to the tally (when we went back to take deaths off the tally)...?

 

[takno]

Brunei, St. Vincent Grenadines, Macao, New Caledonia, Grenada, Saint Kitts and Nevis, Greenland, Falklands, Anguilla & The Holy See. You can easily check it yourself on worldometers. Yes they are all small, however China appears to be only importing casesso is elimanated from the community. It has pretty much gone from Vietnam, Mongolia, Thailand, Cambodia, Laos, Malaysia.

The holy see doesn't even operate as an independent city, let alone a real country. If none of its hundred or so inhabitants happen to have it that just represents the fact that any small community in Rome is statistically unlikely to have it right now. The entire remainder of the first group are islands where it is more possible to pursue zero cases (although its also entirely possible that everybody there got the virus in March and they actually have herd immunity).

In the second group China have had various outbreaks of community transmission over the year, which have largely been dealt with via quite widespread lockdowns. Vietnam has also had substantial community transmission in the last month.

 

[DB]

Go on....tell us which diseases we have acquired herd immunity naturally for...

Meanwhile, recent research has shown that smallpox were first appeared in 8th/9th century Scandanavia and was spread by the Viking raids. Those who survived had lifelong immunity yet it became the deadliest disease in history and was still killing millions until mass vaccination was introduced - absolutely no sign of natural herd immunity there. A commercially created vaccine didn’t appear until the late 19th century and a global campaign for eradiction began in 1958 so eradication happened a lot quicker than you think. The Polio vaccine was invented in 1950 and it is now eliminated from every continent except Asia and then it is mainly Pakistan.

Err, how about many of the respiratory viruses in circulation? It's herd immunity which keeps them at a relatively low level. Sudden increases tend to be due to the viruses mutating.

Or chicken pox and assorted other illnesses primarily associated with childhood.

Herd immunity is of course determined by how many survive and will not build up uf it kills a high proportion of those infected. Have you studied recorded stats for smallpox survival versus new cases over time in particular areas?

 

[takno]

Meanwhile, recent research has shown that smallpox were first appeared in 8th/9th century Scandanavia and was spread by the Viking raids. Those who survived had lifelong immunity yet it became the deadliest disease in history and was still killing millions until mass vaccination was introduced - absolutely no sign of natural herd immunity there. A commercially created vaccine didn’t appear until the late 19th century and a global campaign for eradiction began in 1958 so eradication happened a lot quicker than you think. The Polio vaccine was invented in 1950 and it is now eliminated from every continent except Asia and then it is mainly Pakistan.

Smallpox is, as you mention, quite deadly. You can't develop natural herd immunity to diseases that kill a large proportion of the people who come into contact with them. The case fatality rate of Covid19 is currently estimated at below 0.5% and even lower amongst younger people who are likely to form part of the herd for a long time.

Also, more than 50 years from development of a commercial vaccine to eradication doesn't sound all that quick to me. Nobody is going to wait that long

 

[Philip Elliott]

You think we have herd immunity to the influenza and the common cold? Blimey you really don’t understand herd immunity or virology at all. Millions get colds and flu each year and 600,000 get chicken pox - not something that is seeing its transmission severely restricted.

 

[Richard Scott]

You think we have herd immunity to the influenza and the common cold? Blimey you really don’t understand herd immunity or virology at all. Millions get colds and flu each year and 600,000 get chicken pox - not something that is seeing its transmission severely restricted.

This is the point, they don't kill that many and not everyone gets them. I've never had flu and can't remember last time I had a cold. Herd immunity doesn't mean it doesn't circulate, it does but at a low level. How many people do you know who've had proper flu, I know very few? You want to carry on living like we are be my guest, but many of us are fed up with it and know the risks are very low, a bit like getting into my car, I know there's a risk of being killed in an accident but I calculate it's worth taking the risk.

 

[DB]

You think we have herd immunity to the influenza and the common cold? Blimey you really don’t understand herd immunity or virology at all. Millions get colds and flu each year and 600,000 get chicken pox - not something that is seeing its transmission severely restricted.

You seem to think that herd immunity means that nobody gets it - which is nonsense.

Cold and flu viruses mutate a lot, so of course a good few people will get them. and hence also the flu vaccine has to be modified every year and has limited impact.

The proportion of the population who get chicken pox is a fraction of the total.

 

[Philip Elliott]

Millions get colds and flu each year, it is not at a low level and thousands die each year from flu. You want to let it rip through the population but still expect it to keep on circulating, so how long do you expect the vulnerable to shield?

 

[adc82140]

So you're happy for thousands to die each year from flu, but Covid is somehow different?

 

[DB]

Millions get colds and flu each year, it is not at a low level and thousands die each year from flu. You want to let it rip through the population but still expect it to keep on circulating, so how long do you expect the vulnerable to shield?

It is a low level compared to the total population. This virus doesn't seem to be mutating much, which is good fot the prospect o herd immunity.

As to how long it will keep circulating, probably indefinitely - which is rather the point. Just because people would like it to go away doesn't meant it will, and it is unclear what is being achieved by trying to slow down the spread and therefore also delay any prospect of natural herd immunity. The only justification would be hispital capacity, but that us not under any threat at the moment.

 

[Philip Elliott]

Who said I am? We need to increase the use of the flu jab but ultimately the rapid mutations means we are always one step behind. Why are you okay okay for people to die ftom covid?

 

[Yew]

Brunei, St. Vincent Grenadines, Macao, New Caledonia, Grenada, Saint Kitts and Nevis, Greenland, Falklands, Anguilla & The Holy See. You can easily check it yourself on worldometers. Yes they are all small, however China appears to be only importing casesso is elimanated from the community. It has pretty much gone from Vietnam, Mongolia, Thailand, Cambodia, Laos, Malaysia.

Bustling metropolises! (metropolii?)

 

[DB]

Who said I am? We need to increase the use of the flu jab but ultimately the rapid mutations means we are always one step behind. Why are you okay okay for people to die ftom covid?

It's irrelevant whether or not someone is ok with it - it is simply the reality and pretending otherwise helps nobody.

 

[Philip Elliott]

It is a low level compared to the total population. This virus doesn't seem to be mutating much, which is good fot the prospect o herd immunity.

As to how long it will keep circulating, probably indefinitely - which is rather the point. Just because people would like it to go away doesn't meant it will, and it is unclear what is being achieved by trying to slow down the spread and therefore also delay any prospect of natural herd immunity. The only justification would be hispital capacity, but that us not under any threat at the moment.

The reproductive value of flu is very low and general hygiene are the main factors over the number of annual cases.

 

[Yew]

Why are you okay okay for people to die ftom covid?

I don't think we are, I'd dearly love for some sort of magic bullet to stop it circulating but I fear that it's unlikely to happen, and the damage done through trying, or hoping and waiting is worse.

This disease in endemic in the human population, we can't do anything to stop it. Pandoras box is open, and the world is worse now.

 

[Richard Scott]

Who said I am? We need to increase the use of the flu jab but ultimately the rapid mutations means we are always one step behind. Why are you okay okay for people to die ftom covid?

Don't think anyone is ok with people dying but it is an inevitable consequence of life. The point is many that die from it are nearly at the end of their life and likely will have health issues. We are causing other issues carrying on trying to prevent these deaths most of which would have occurred within a couple of months anyway. This isn't a one horse race, whatever we do has a knock on effect somewhere else. Seems a lot aren't prepared to accept this is the case and those of us who are seem to be considered callous. Afraid a good reality check is needed.

 

[GRALISTAIR]

I am of the herd immunity brigade.

 

[trainophile]

Is it abhorrent to infer that there may be a certain amount of Darwinism in the current situation? Out at friends' house last night (just four of us in total!) and the point was raised that there are too many people currently on earth for sustainability. Therefore nature is dealing with this in her own way, whether we like it or not.

Which means that however much we try to suppress this virus, we won't win until the planet and its resources stabilise.

 

[adc82140]

Is it abhorrent to infer that there may be a certain amount of Darwinism in the current situation? Out at friends' house last night (just four of us in total!) and the point was raised that there are too many people currently on earth for sustainability. Therefore nature is dealing with this in her own way, whether we like it or not.

Which means that however much we try to suppress this virus, we won't win until the planet and its resources stabilise.

Not at all. For the last generation there has been focus on keeping people alive as long as possible at all costs. 20% of 80 year olds have dementia. I'm sure I wouldn't want to be kept alive just to sit unable to control my own bodily functions. Harsh as this sounds, Covid may be a bit of a leveller here. I have elderly relatives who fit in to that age bracket, and they are certain that they'd prefer to die quickly of a respiratory disease than linger on with no quality of life.

 

[takno]

Is it abhorrent to infer that there may be a certain amount of Darwinism in the current situation? Out at friends' house last night (just four of us in total!) and the point was raised that there are too many people currently on earth for sustainability. Therefore nature is dealing with this in her own way, whether we like it or not.

Which means that however much we try to suppress this virus, we won't win until the planet and its resources stabilise.

It's not abhorrent at all, but I don't think environmental resources or the lack of them has much of anything to do with whether we can suppress Covid. In any case as a population reduction mechanism you'd want something that killed off a bit more than 0.5% of infected people, and preferably didn't mostly affect people close to the end of their lives.

 

[C J Snarzell]

Given how long this fiasco is going to go on for, it seems likely the next parliament will probably implement an exit strategy!!!

Very unlikely Matt Hancock will be in post too long. He's starting to come across now as the nervous school boy wanting to ask his teacher if he can go to the toilet.

CJ

 

[HSTEd]

Go on....tell us which diseases we have acquired herd immunity naturally for...

You won't have heard of them because they will not be significant viruses any more.
The whole point is that evolution is an arms race.

Lots of viruses disappear all the time!
The ones you've heard of are just the relative few that have resisted herd immunity for significant periods.

Vast numbers of people don't still die of the 1918 Flu Pandemic virus do they?
It is also well known that smallpox was becoming less deadly prior to the deployment of vaccinations.

 

[island]

Bustling metropolises! (metropolii?)

Right first time. I looked it up to check, because I had thought, incorrectly as it turns out, that the plural would have been “metropoles” in the same way as crisis/crises.

 

[yorkie]

Brunei, St. Vincent Grenadines, Macao, New Caledonia, Grenada, Saint Kitts and Nevis, Greenland, Falklands, Anguilla & The Holy See. You can easily check it yourself on worldometers. Yes they are all small, however China appears to be only importing casesso is elimanated from the community. It has pretty much gone from Vietnam, Mongolia, Thailand, Cambodia, Laos, Malaysia.

To quote Arnold J Rimmer, "Well, I don't know about you, but I'm convinced" (!)

Are you seriously suggesting we could adopt similar tactics to China?

And do you think what's currently happening in Ruili could be done here?

 

[Yew]

An interesting discussion here around the potential harms that social distancing may cause, from Prof Francois Balloux

https://twitter.com/BallouxFrancois/status/1307381114584141825

The instantaneous risk (i.e. at any time point) for a vulnerable person to get infected with #COVID19 in a random mixing population is simply the prevalence of the virus in the population.

Though, if we assumed that a % of a population will get infected eventually before the epidemic recedes, the entire population social-distancing increases the proportion of 'at-risk' people getting infected, relative to a scenario where only at-risk people sheltered.

The risk of #COVID19 to different demographies is highly variable, with elderly being at >1,000x higher risk than young people. As such, a reduction in the number of infections, but leading to a higher proportion of elderly being infected can lead to a higher death toll.

Let us assume that 50% of the population could get infected by #COVID19 before a vaccine is available. We divide the population into a high-risk (10% >75 years old; IFR~10%), and low-risk group (90% <75 years; IFR~0.2%). Now consider two countries both with 10M inhabitants.

In country A, everyone social-distances, with considerable success. As a result only 10% of the population gets infected. Though, as everyone social distances, the risk of infection is similar for everyone. This leads to ~10,200 deaths.

In country B, no one outside those in the high-risk group takes precautions. As a result 50% of the population gets infected. Though, those in the low-risk group are 10x more likely to get infected. This leads to ~6,000 deaths, about 60% of the death toll of country A.

In this hypothetical toy example, country B is likely in a better situation not only because it experienced fewer deaths but also because a far larger proportion of the population has been immunised (50% vs. 10%).

This toy example is not particularly realistic nor carefully parametrised and does ignore several important considerations. There are also challenges to implement an effective strategy to protect the 'at-risk' population in a humane and effective way.

That said, the toy example illustrates that population-wide 'social distancing' and lockdowns are not necessarily the most effective strategies to minimise the death toll of #COVID19, even when ignoring the collateral damage of invasive public health interventions.

 

[ChrisC]

I was listening to the radio this afternoon and heard an interesting report from France. There have been huge increases in the number of new cases in France these last few weeks but this second wave may be following a different pattern to the first wave. The report suggested that the virus is becoming far more contagious but less deadly.

 

[yorkie]

I was listening to the radio this afternoon and heard an interesting report from France. There have been huge increases in the number of new cases in France these last few weeks but this second wave may be following a different pattern to the first wave. The report suggested that the virus is becoming far more contagious but less deadly.

This is broadly correct and has been posted on several threads already

It's unclear if the D614G variant which is more prevalent now is definitely more contagious but less deadly than the earlier form of the virus, but you are right that there are a lot of reports suggesting this is the case.

However there are also other factors that may be contributing to what we are seeing; I explored these possibilities in the following post:

Covid : Infection rates v death rates and a possible second wave

One study I would like done is a follow on a survey of all those who who have had a positive covid test, probably after 28 days How many have had 1/ No symptoms (Asymptomatic) 2/ Very mild symptoms that probably normally would be ignored 3/ Ill but not seriously enough to go to hospital 4/...

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