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Another alternative view - article by Sunetra Gupta, Professor of Theoretical Epidemiology at the University of Oxford who wrote the 'other' report we remember from back in March.
https://unherd.com/2020/05/oxford-doubles-down-sunetra-gupta-interview/
Best to read the whole thing but maybe this is the summary:
“In almost every context we’ve seen the epidemic grow, turn around and die away — almost like clockwork. Different countries have had different lockdown policies, and yet what we’ve observed is almost a uniform pattern of behaviour which is highly consistent with the SIR model. To me that suggests that much of the driving force here was due to the build-up of immunity. I think that’s a more parsimonious explanation than one which requires in every country for lockdown (or various degrees of lockdown, including no lockdown) to have had the same effect.”
(I'm not endorsing it merely sharing it, and obvs an academic is going to want to defend their prediction so there's potential for bias.)
I suppose its possible, but she has to turn theoretical epidemiology into hard epidemiology at some point with some evidence to support it apart from some similarities between the death curves between countries with varying levels of lockdown.
At what rate would the virus have to be transmitted to get from 0 to 50% incidence in a population of 60 million in just a few months?
Anyone who has posted on this thread Know anyone who has tested positive for covid 19 ?
Know several families who think that they've had it. My mates wife is in the NHS and several of her team have had it. A team colleague at work's father passed from it, and she then ended up on a ventilator. Another ex colleague is currently on a ventilator.
Sunetra Gupta
Again? FFS, will people not learn.
Attention seeker. Ignore.
Quite a good explanation of memory cells etc.
(Or I thought it was.)
Sunetra Gupta
Attention seeker. Ignore.
I don't doubt it, but please link to a credible source saying that so we can make up our own minds.
Also link to a credible source debunking something in the article?
At what rate would the virus have to be transmitted to get from 0 to 50% incidence in a population of 60 million in just a few months?
At the rate we were told it was being transmitted a few months ago.
We were told two months ago that 1% of the population had been infected. It was doubling every 2-3 days. R was around 4.
with regards to that interview, the following is pertinent:
Observing the very similar patterns of the epidemic across countries around the world has convinced Professor Gupta that it is this hidden immunity, more than lockdowns or government interventions, that offers the best explanation of the Covid-19 progression:
It did not dawn on her, perhaps, that the reason they were so similar is that they followed the same actions - unrestricted exponential growth (doubling every 2.8 days in UK), followed by containment. Easy to speculate on "hidden immunity" - cross reactivity due to past Corona virus infections that one cannot detect. Maybe. Except there is also Antibody Dependent Enhancement, where instead of immunity, low levels of antibodies make infections WORSE by facilitating cell invasion via another receptor (Fc).
Frankly the serology in multiple countries, the Sweden experiment (where R is basically held at 1 and has remained so for weeks, with 7% seroprevalence not their predicted 40%), and the nature of the natural dynamics of epidemic growth points to the lockdown being a reasonable intervention in the absence of treatment or vaccination.
At the rate we were told it was being transmitted a few months ago.
We were told two months ago that 1% of the population had been infected. It was doubling every 3 days. R was around 4.
...and is 50pc a crude estimate of a level where the virus peters out or is it more nuanced than that? Supposing 20pc of us had had it but they were the *right* people. We know it's been rife in care homes and hospitals. Perhaps it's run out of vulnerable spreaders and the rest of us just don't catch it and spread it that well.
Hopefully some of STW's more knowledgeable people might step up and link to some decent theories on why relaxing lockdowns across Europe hasn't resulted in a jump in infections.
Without any restriction of contacts and a wholly susceptible population (we can all catch it), infections double every three days. In most countries. If there is some immunity, the supply of new people dwindles and the infection cannot keep going. Variously that proportion is 1-1/R (so about 2/3). Now that assumes everyone mixes with everyone else. If we mix a bit less, then you have shorter transmission chains and not such a high proportion.
Relaxing lockdowns is not going back to where we were three months ago.
If you have N people in a room, there are N(N-1)/2 possible contacts. We've gone from 4 people in out house 6 contacts, to plus one more person outside. 6 + 4 = 10. This is a supertanker, so you will not see huge rapid spikes.
THanks Tired, I hoped you'd explain it all!
perhaps, that the reason they were so similar is that they followed the same actions
I'm going from memory, but weren't there differences: Italy's lockdown seemed to take an eternity to have an effect, while New York's worked overnight. ...and then there's Sweden.
the Sweden experiment (where R is basically held at 1 and has remained so for weeks, with 7% seroprevalence not their predicted 40%),
They did have a peak of deaths and it was around where everyone else's was. You're saying antibody tests suggest it didn't spread much in Sweden after all when you'd expect 40pc to have had it? So does that mean either that it's less infectious than we thought or that Sweden's social distancing measures were effective? Or something else?
lockdown being a reasonable intervention
Yup, no quarrel with that, I'd be doing the same if it were my call.
Without any restriction of contacts and a wholly susceptible population (we can all catch it), infections double every three days. In most countries. If there is some immunity, the supply of new people dwindles and the infection cannot keep going. Variously that proportion is 1-1/R (so about 2/3). Now that assumes everyone mixes with everyone else. If we mix a bit less, then you have shorter transmission chains and not such a high proportion.
Yup.
Relaxing lockdowns is not going back to where we were three months ago.
If you have N people in a room, there are N(N-1)/2 possible contacts. We’ve gone from 4 people in out house 6 contacts, to plus one more person outside. 6 + 4 = 10. This is a supertanker, so you will not see huge rapid spikes.
Are you saying nowhere has relaxed the most effective elements of their lockdowns yet so the gentle relaxation so far has had no effect and they aren't seeing more cases??? (Presumably people are begin hyper careful too.) If/when they returned to normality (unless there's a vaccine) they *will* still get big spikes???
variously that proportion is 1-1/R (so about 2/3)
That's with R=3.
But if R drops to e.g. 1.5, you only need 33% of the population to be infected to reach that herd immunity.
Last time the government reported on it, we were actually at R=1, though I have no idea if that's still (or ever was) true.
But at what level is it basically "good enough" ?
Sweden's epidemiologist is back-pedaling as fast as Gupta will be. As is their modeller. They predicted 40% prevalence by May 1. Note I did not say that the Sweden "experiment" was a bad one. it's not unreasonable given their delay behind us and timing, but they have done worse than their neighbors.
Truth is, this is a moderately contagious respiratory disease, with high morbidity and mortality in the elderly (as per nasty influenza), but no treatment or protection other than behavioral changes, which we took. We took it in good faith for robust reasons based on robust predictions from multiple sources.
But if R drops to e.g. 1.5, you only need 33% of the population to be infected to reach that herd immunity.
But surely if that 'R' is being achieved by lockdown, social distancing, shielding etc then you have to maintain those measures. Don't we have to get to the % that is required for a R value that is the one that results from 'business as usual'?
I.e. >60% (?)
Truth is, this is a moderately contagious respiratory disease, with high morbidity and mortality in the elderly (as per nasty influenza), but no treatment or protection other than behavioral changes, which we took. We took it in good faith for robust reasons based on robust predictions from multiple sources.
Yup, there seems no doubt at all that lockdowns were a the right course of action for all kinds of reasons.
Many thanks, I think I've taken enough of your time. much appreciated, as always.
You either play the long-game for herd immunity - infect as many as possible with R > 1, and once you get to about 50% you start to exhaust susceptibles (until more are born or immunes lose their immunity). Or you keep contacts down and R < 1 and wait till it dies out naturally.
Sweden have maintained a roughly constant incidence of new cases so R = 1. But the LOW incidence means it will take a loooong time to get to significant prevalence.
If we have a vaccine, herd immunity will come from that, not infections. If we don't it will be track, trace and treat index and contacts. With no eventual population protection.
With no eventual population protection.
I.e. it just becomes a fact of life (along with the individual surveillance)?
Eek. Need that vaccine!
Sweden have maintained a roughly constant incidence of new cases so R = 1. But the LOW incidence means it will take a loooong time to get to significant prevalence.
Yup, so Sweden did something different to everyone else and peaked about the same time as everyone else. So what's the 'conventional' view on why that happened. Is there one?
So what’s the ‘conventional’ view on why that happened. Is there one?
Lower population density is going to be a major contributing factor, Shirley?
My view from the Sweden experiment is that if you relax lockdown, maintain some sense of caution and try and protect the elderly properly (especially in nursing homes), then R is about 1 for this disease. If we bring UK incidence down to similar low levels (by lockdown with R < 1) then do the same, we will also have R about 1, but infections will not blow up (because R is 1 not 3!). The key is to decide what daily level is OK (because at R = 1, that's what you will see every day).
Lockdown is very effective, but it is, of course, not sustainable.
Oh, and it's not population density - sorry. Sweden isn't really any different. You have to count the density where people actually live 🙂
My view from the Sweden experiment is that if you relax lockdown, maintain some sense of caution and try and protect the elderly properly (especially in nursing homes), then R is about 1 for this disease. If we bring UK incidence down to similar low levels (by lockdown with R < 1) then do the same, we will also have R about 1
Thanks that's clear and certainly explains what we're seeing.
Oh, and it’s not population density – sorry.
Don't be sorry!
I am sorry for lazy conjecture...🙂
I seem to recall that rather than population density per se, Sweden has a higher proportion of single person households, which was thought might reduce transmission rates.
That may have come from an article about a month ago and be out of date by now.
Maybe the prevalence of single-person households in Sweden influenced their decision to make a rational judgement of what precautions could reasonably be suggested, rather than adopt a draconian lockdown espoused by a ruling class that disregards the rules which it promulugates for the plebs.
Sweden has a very high proportion of single person households.
It’s also not remotely true that we didn’t, or haven’t, implemented social distancing.
And arguably we were told to be alert before it was cool, with information about what alert means.
Ordinarily I would have come into physical contact with people or things people had touched hundreds of times per day. Swedes are (were) as physically tactile as they are socially distant. Since CV I can’t remember the last time I touched another person and have 3 different levels of hand washing depending on the level of CV-risk/dirt.
I read something to the effect that in a poorly ventilated space you’d need >10 minutes of breathing at each other or >5 minutes of talking to make a worse than evens chance of transmission. Outside there is almost no chance of transmission. All the pictures you’re seeing are people outside - and mostly with that great ‘journalistic’ telephoto lens trick.
Something in the stories about Sweden that somehow never makes the news is the change to social security that sick pay (which is nearly 100% salary) is now paid from the first day of illness which means that everyone* can afford to make the right decision about staying out of the workplace if they have symptoms.
Our epidemiologist is the first to critique his own early choices about care homes (where 75% of the deaths have occurred) and crucially the vast majority of the country believe that lessons will be learned for later in this crisis and the next one.
Junior schools are open but most schools are outside most of the day and parents aren’t allowed inside.
My concern now is that Sweden chose such a sustainable ‘lock down’ that we’ve become altogether too comfortable with social distancing and that normal is further away than it will be for countries that went into unsustainable lock down and quickly back to open again.
I probably won’t post again unless I can solve the cookie consent pop up thing.
*Everyone. Always deserves an asterisk.
This tracking app. From what I understand they have been using one in south Korea for weeks and it's open source code. So why the hell do they need to create one from scratch instead of copying it and changing the language.
Same with the ventilators couldn't they have copied an existing design instead of paying 20m to develop something that was never used.
Are we being take for a ride.
Im not sure how Gutpa & Sikora are getting away with posting their theories without having any actual studies to back them up
the studies that have been done seem to say that they are wrong & its a much lower % with immunity
The danger is that people that believe them are going to be spreading it willy nilly, thinking we likely have immunity
Wasn't there supposed to be a quarantine period for arrivals announced this week? Did I miss it?
the studies that have been done seem to say that they are wrong & its a much lower % with immunity
Magic undetectable immunity. The most obvious explanation is obvious and unpalatable To that group. Popper’s philosophy of science was wrong.
Social media makes everyone an armchair epidemiologist and expert in statistics 😀
I know it’s only Oxford, but I doubt they hand out chairs in epidemiology to anyone. Doesn’t mean she’s right of course, but both sides in this discussion seem keen to rubbish any expert that doesn’t agree with them.
By the way, is the shape of the curves for different regions (and different countries) consistent with the idea that lockdown is the main thing reducing spread?
I still don’t understand why London is falling so fast while other parts of the country are not. I hear the argument that those other parts are behind London, but we all went into the same lockdown at the same time. So, if it is lockdown that drives the decline would we not expect all regions to show similar declines?
Could possibly be due to very few people going into London right now and lots of people who live there having bolted to their country houses instead. By all accounts the place is a ghost town so that would really help stop any spread there.
The Gupta thing.
One cast-iron way to see she is talking nonsense is to realise that there are multiple large areas around the world with different demographic and economic structures where the total mortality is already over 0.1% - and that despite disease suppression efforts in these areas.
Guayas in Ecuador. Young population. 0.27% dead.
New York. Lombardy. Even London is close. Madrid.
Anything under 0.4% for a fatality rate is basically out the window.
If London has significantly higher infection rate as per Mancock yesterday that would certainly push their curve down compared to rest of UK. Simple models probably underestimate this effect which I expect to be quite significant at the 17% level as those 17% will tend to be the most socially active and healthcare staff etc who will have very high personal R values. Once they are immune the population average for the rest will drop.
This tracking app. From what I understand they have been using one in south Korea for weeks and it’s open source code. So why the hell do they need to create one from scratch instead of copying it and changing the language.
I’d have to ferret about the code to confirm but from the tech descriptions of it but I think it’s very similar to the nhsx, same sort of ingredients Bluetooth pinging and a fire base back end (Google Cloud stuff)so to me they smell very samey.
The issues with the hardware not the software, although this causes issues on the iOS phones as they helpfully attempt to power save and switch it off,just having your Bluetooth having to pulse continuously nibbles away at the battery life, everything’s a bit of a fudge to not gobble up your battery.
The apps are better than nothing but they’re not magical and if this becomes a thing then we’ll probably see various tech coming out that copes with the pinging requirement.Bigger batteries 🙂
They do seem to have done some interesting tweaks To get around the iOS issues.
To help users keep the app running in the foreground while minimising battery usage, the TraceTogether team included a power saver mode setting in the codebase. If you are an iPhone user, all you have to do is keep TraceTogether open but place the phone upside down in your pocket or face down on the table. That will trigger the power saver mode, allowing the app to regularly scan the environment for other TraceTogether users.
TLDR House is sceptical that it’s any different to ours 🙂
@thecaptain So, Are you saying that the steep falls in London are being driven by immunity rather then the lockdown, which (based on the curves for other areas) only gives you a gentle decline.
I’m not sure how infection-fatality rates are calculated. How do you account for all those people with significant co-morbidities for example? If you count anyone who dies with CV as a death from CV then wouldn’t that affect the infection-mortality rate of all the other things they might have died from? As I say, it’s not my area, but I would have thought that the effect of co-morbidity would be included when they finally calculate the infection-mortality rate for CV so just taking stated deaths in New York for example and dividing by population may not be a very good guide. I’d agree that the good professor seemed to lack a clear answer to that question when it was presented to her though.
If you count anyone who dies with CV as a death from CV then wouldn’t that affect the infection-mortality rate of all the other things they might have died from?
As I understand it, this is why those in the know are looking at total excess deaths from ONS data that is a week or so behind?
As I understand it, this is why those in the know are looking at total excess deaths from ONS data that is a week or so behind?
I am. There was a significant drop in all-cause deaths this week - and the effect is much more sensitive than simply COVID19 deaths. I think it might be a possible barometer to look at changes as we relax lockdown.
My issues with Gupta are largely that in the face of multiple global serology studies finding that the prevalence is 3-10%, rather than accept (as one would for every other viral infection) that this is likely to be the prevalence, the explanation must be that a mythical 40% have not generated antibodies despite having had the infection. She made a prediction (sort of), it has been found wanting.
By contrast, Sweden just said "we were wrong and the assumptions in our models need refinement".
We have also apparently been attributing deaths in the country to COVID more than others. The example I was given yesterday was that we (Sweden) attribute all deaths with a COVID-related cause to COVID and list them as such, whereas other countries have seen a really big spike in pneumonia-related deaths, but very low COVID (*cough* Russia). That is apparently skewing the figures upwards an giving a slightly false impression of infections and deaths.
I really need to read more of the local news sources to get a better idea of what is going on.Sadly, my statistical and immunology Swedish is quite poor.
Are you saying that the steep falls in London
I'm still wondering if London had it a lot earlier than is being shown/we know. Based purely on the fact I went sick and was signed off work for a week in February with a mystery flu like illness, that nobody around me had before or after I did. It last 7+ days and took me 3 weeks to get back to normal.
In January I spent a very significant amount of time travelling around the UK using the Tube and London stations as a Hub, did I catch COVID19? I didn't have more than a very minor cough so probably know, but I did have breathing issues which I attributed to my normal asthma, but you never know.
So what’s the ‘conventional’ view on why that happened. Is there one?
A mate of mine married a Swedish lass last year and moved over there. His take is that Swedish people are more amenable to rules than Brits generally, but also, as above, social distancing is still very much taking place albeit within a more relaxed framework. So cafes are open, but set up with large spaces between tables for example and only one person allowed inside at a time. Shops have perspex shields to reduce risk etc.
The idea that life is going on as normal there, isn't, according to him, remotely the case, it's more that culturally the population is more inclined to comply with suggested rules and norms without high profile enforcement. That's his take anyway.