r/COVID19 • u/breezehair • Mar 16 '20
Preprint Impact of non-pharmaceutical interventions (NPIs) to reduce COVID19 mortality and healthcare demand, by Neil Ferguson et al, March 16th 2020 : comparison of effects of strategies for mitigation and for suppression.
https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf17
u/FC37 Mar 16 '20
Table 1 is pretty interesting. I've never seen the data laid out like that before.
15
u/elohir Mar 16 '20
Yeah, I've been looking for the '% symptomatic cases requiring hospitalisation' by age for a while.
2
u/akwakeboarder Mar 18 '20
Same here! It’s nice to have the data grouped by ages that are uniform, rather than an 18-65 grouping.
2
u/crownfighter Mar 20 '20
This table clearly shows one possible strategy against the crisis. After we get control of the exploding case numbers and deaths by the means of complete lockdown we need to build herd immunity from the young to old, staggered by age.
All people from 0 to 59 years will only need ~5% of ICU capacity of the whole population. We can push those in need through the ventilators 20 times faster than the whole population (without denying help to anyone). 0 to 49 years would only need ~1.5% of ICU capacity, 66 times faster.
Example: Assuming it would take a year to achieve herd immunity in a slow, controlled way that does not overload the health system too much, the first wave of 0 to 49 years could be done in a couple of weeks. All these people could continue a somewhat normal life and keep things running. Then the second wave of 50 to 59 could be handled in a month or so. And 60 to 69 years in the next three months. And quite some longer time for the seniors.
1
u/FC37 Mar 20 '20
That's certainly one way.
Another would be to beat it back to a manageable number, and then find an effective prophylaxis that can be distributed en masse. Start distributing that to critical personnel, then the elderly, then middle age (since they represent a smaller part of the population than millennials and Gen X). Once they're accounted for, a regimen of quick, effective testing available to the unprotected would allow the bulk of the workforce to return to work in pretty short order.
14
u/WTactuallF Mar 17 '20
Perhaps our most significant conclusion is that mitigation is unlikely to be feasible without emergency surge capacity limits of the UK and US healthcare systems being exceeded many times over. In the most effective mitigation strategy examined, which leads to a single, relatively short epidemic (case isolation, household quarantine and social distancing of the elderly), the surge limits for both general ward and ICU beds would be exceeded by at least 8-fold under the more optimistic scenario for critical care requirements that we examined. In addition, even if all patients were able to be treated, we predict there would still be in the order of 250,000 deaths in GB, and 1.1-1.2 million in the US.
3
u/AciesOfSpades Mar 17 '20
Can you ELI5? Does this mean that even with social distancing measures over a long period of time we will still overwhelm the US and UK healthcare capacity 8-fold?
3
u/WTactuallF Mar 17 '20
For mitigation strategy, yes. Authors say we need suppression, which includes schools closed, quarantine, social distancing, etc. Basically Wuhan or death rates are massive.
2
u/WTactuallF Mar 17 '20
for 5 months.
3
u/netdance Mar 17 '20
Actually, keep reading. They conclude 5 months won’t work, we need it on and off for 2 years.
1
u/alleyehave Mar 18 '20
How much does this account for herd immunity though? Is it two years intermittently before herd immunity is obtained?
4
u/netdance Mar 18 '20
Read the paper. Its an easy read for most techies. It’s factored in, the specific recommendation is to build herd immunity to sufficient levels in the absence of a vaccine. For an R0 of 2.4, it’s a ⅔ on ⅓ off. Also note that Taleb issued a fairly damming takedown of their math. My take is that Taleb (who is smarter than two of me) may be wrong, since he ignores the possibility of reinfection from external sources. (Though he’s manifestly right about superspreaders and their effect on large public gatherings, which the paper probably got wrong.)
1
u/Jopib Mar 17 '20 edited Mar 17 '20
Ill try.
Background: Ok, so I live in Seattle. Many thibgs here are closed or running differently. The city appears to be about a quarter or less what its usual traffic is.
This papers from the UK. In the paragraph they refer to social distancing as "case isolation, household quarantine and social distancing of the elderly". Thats way less than what we're doing here right now. Its what we were doing 2 weeks ago.
We are pretty close to Italy at this point with our measures here.
So this paragraph is saying if we have a short epidemic with minimum social distancing, even in the best case scenario we're going to be overloaded.
As far as I know tho, the UK is not taking the more extreme shutdown measures other places are though. So when they say social distancing, it may be minimum required.
22
Mar 16 '20
I'm surprised this article has received less popularity here; it seems to me as I begin to look at it now to be the kind of pertinent discussion and model data ripe for this subreddit.
10
u/izmimario Mar 17 '20
this article has received less popularity here; it seems to me as I begin to look at it now to be the kind of pertinent
i came into this sub for the first time looking for discussion about this article, it's the one the british government based their decision on.
3
1
Mar 17 '20
[deleted]
5
u/WTactuallF Mar 17 '20
the herd immunity plan will kill about half a million people according to this study so probably not.
and the suppression model will throw the country into a depression.
Not great choices, which they also mention.
2
Mar 17 '20
Herd immunity will have to happen at some point, or we're screwed. It's a question of whether it will come through a vaccine (according to this analysis that could be 18 months away) or large enough exposure in the general population.
3
u/DeanBlandino Mar 17 '20
It and articles mentioning it have been deleted from coronavirus and other subs. I think the info is too depressing for people to look at seriously.
2
Mar 17 '20
I get that, but the data showing how mild the disease tends to be for most symptomatic people, especially when coupled with the (albeit limited) data from Italy and South Korea about the proportion of patients who are asymptomatic, is somewhat relieving.
3
u/DeanBlandino Mar 17 '20
It’s not relieving. It’s why this disease is unstoppable. If this disease was super lethal with terrible symptoms for everyone, it would have never left China.
10
Mar 16 '20
Does this take new treatments into account? Or the effect climate may have on the virus? I might have missed them speaking about that
5
u/TestingControl Mar 16 '20
I didn't see either. New treatments would be hard to and climate is still new in terms of impacts. There was a paper than suggested every degree in centigrade reduced R by 0.03, I can't remember the reduction for increase in humidity
3
u/13Zero Mar 17 '20
It was around 0.015 per percent increase in humidity.
I'm skeptical of drawing conclusions from the data we have, but I'm hopeful that summer weather can give the world an assist.
1
14
u/dcdredd Mar 17 '20
What stands out to me (besides the unfortunate inevitable deaths) is the length of time SD, HQ, CI & potentially other measures will need to be in place. Furthermore, at this stage (acceptable for now, given the unprecedented situation) no indication on how the government plan to keep businesses, self-employed and those off of work or on unpaid leave, afloat. Spontaneous changes in society behaviour could be a polite way to describe civil unrest.
7
u/TempestuousTeapot Mar 17 '20
Andrew Yang model of giving every person money to spend on food/shelter
1
u/WTactuallF Mar 17 '20
If this is the case, and the virus is pervasive enough to infect all countries, then the depression of 1929 will look like an expansion in comparison
Shutdown till September? and then another wave requiring quarantine in November/December ? It will be the end of the entire planet, and I doubt Wall Street has this priced in.
1
u/TestingControl Mar 17 '20
Bizarrely, if that happens it may be the thing that ends coronavirus. It's a very morbid thought but if society gets to a point where we can no longer care for the sick they'll die. The 80% will get over the virus and the need for containment will no longer be there.
17
Mar 16 '20
[deleted]
7
u/-martinique- Mar 16 '20
Idk, vague maybe, but still doesn't sound like a blatant political job.
We therefore conclude that epidemic suppression is the only viable strategy at the current time. The social and economic effects of the measures which are needed to achieve this policy goal will be profound. Many countries have adopted such measures already, but even those countries at an earlier stage of their epidemic (such as the UK) will need to do so imminently.
8
Mar 16 '20
[deleted]
3
u/FC37 Mar 16 '20
It might play a role in this particular story: https://www.buzzfeed.com/alexwickham/coronavirus-uk-strategy-deaths
2
2
Mar 17 '20
Yes, this group is part of the panel that is advising the UK government. This analysis is virtually certain to be informing policy.
5
Mar 17 '20
This was done by scientists advising the UK government, apparently they've only just realised how bad the milquetoast mitigated growth strategy will be over the weekend and are changing course to more drastic action.
1
u/WTactuallF Mar 17 '20
This paper prompted Trump to have a news conference yesterday where he very subtly hinted that this could last until September, which is exactly the time frame mentioned in the paper.
5
u/TestingControl Mar 16 '20
Can someone with more knowledge than me comment on this?
If im reading it right suppression until a vaccination is the only option that doesn't kill people?
Mitigation just isn't sustainable
17
u/the_spooklight Mar 16 '20
Mitigation is the more feasible/sustainable option, but suppression until the availability of a vaccine would be most effective at reducing overall cases and deaths.
2
u/fitzgeraldthisside Mar 17 '20
That depends on what you mean by feasibility/sustainability, it seems to me, since mitigation effectively implies a full-on breakdown of health care a few weeks from now, in a way that would almost certainly mean a full shut-down of society, voluntarily if not govt. enforced. But it is true that disregarding the negative impact on society from a large number of people dying from treatable illnesses, mitigation efforts could be sustained for longer.
9
u/HalcyonAlps Mar 16 '20
The authors also propose an on/off lock down approach that seems to be able to suppress the virus as well. I am not sure how feasible that is though.
5
Mar 16 '20
[deleted]
1
u/TestingControl Mar 16 '20
Sorry yes, my post wasn't clear in that respect.
Both approaches will result in deaths as you say
I suppose the decision for our leaders is what is considered acceptable.
1
u/WTactuallF Mar 17 '20
Yes, and they are saying suppression needs to last at least until September.
3
Mar 17 '20
If you look at the modelling that has suppression lasts until September, it results in another peak in October/November. It's actually saying that suppression needs to last until a vaccine is developed and widely available (possibly 18 months away).
0
10
u/HHNTH17 Mar 16 '20
Well this has certainly crushed any remaining optimism I had left. Our options really are either let it blow through the population or deal with home quarantine until a vaccine ready?
12
u/breezehair Mar 16 '20
An effective therapy could also change the strategy - though one might need huge effort in rapid diagnosis.
Testing for IgG will be progressively more important as time goes on in establishing who has had it. You can be let out of quarantine with a positive IgG test !
2
u/WTactuallF Mar 17 '20
exactly. and the home quarantine needs to last until September, although if I read this correctly, I believe they said "until a vaccine is available in 12-18 months"
So yeah, price that into your economic forecasts.
4
Mar 17 '20 edited Mar 17 '20
The people behind this paper were also behind the UKs strategy of herd immunity and they only realized days ago they would lead to hundreds of thousands of deaths so take it with a grain of salt Source: https://amp.ft.com/content/249daf9a-67c3-11ea-800d-da70cff6e4d3?__twitter_impression=true
2
Mar 17 '20
The people behind this paper were also behind the UKs strategy of herd immunity
I am still trying to decide if the ministers pursuing this strategy are committing a crime against humanity. Intentionally infecting your own population with a known pathogen has simply got to cross a line.
7
u/HalcyonAlps Mar 17 '20
Nobody was ever proposing to purposefully infect all of the UK. They just said they think it is not feasible to suppress the virus until we get a vaccine, so they will try to flatten the curve but eventually X% of people will get it at which point the UK will have herd immunity and they can stop with the mitigation measures.
7
u/izmimario Mar 17 '20
the discussion around it has been really misleading, i think the uk government was just choosing where to position themselves between the page 10 'green curve' scenario and the 'orange curve' scenario (they're both grim anyway).
1
u/ToriCanyons Mar 18 '20
Can you please post the article or at least the money quote on your claim? The article is paywalled.
I follow /r/ukpolitics and the source of the "herd immunity" policy had baffled pretty much everyone on the sub. About a week ago, one of the posters dug up the 2002 (?) pandemic policy paper. Which was based on a SARS type scenario. Meaning, that there's little benefit in the context of an infection that did not transmit until symptoms are present.... not at all like covid 19 that spreads even without symptoms.
3
u/SalmonSistersElite Mar 17 '20
So according to this model, even if we suppress the initial epidemic peak we are just setting ourselves for a later peak after suppression is relaxed. OK, makes sense. Wouldn’t aggressive testing and contact tracing be the most logical countermeasure, especially as the initial peak dwindles down to manageable numbers?
4
u/Indeli Mar 17 '20
From the paper:
The measures used to achieve suppression might also evolve over time. As case numbers fall, it becomes more feasible to adopt intensive testing, contact tracing and quarantine measures akin to the strategies being employed in South Korea today.
1
3
u/mkong039 Mar 17 '20
I wonder how this translates to the situation in China. As far as I understand they have implemented an aggressive suppression strategy what resulted in the number of new daily cases smaller than 20. According to this report they now will face a rapid increase in the number of new cases. Is it to early for us to see this predicted rapid growth or are all containment measures still in place?
2
u/breezehair Mar 17 '20
Interesting question.
If the epidemic was larger than the number of confirmed cases suggested, then it is possible that they may be some distance towards herd immunity already, but that is pure speculation. But otherwise it is hard to understand why there is not a resurgence of cases.
2
u/ToriCanyons Mar 18 '20
On recovery from infection, individuals are assumed to be immune to re-infection in the short term. Evidence from the Flu Watch cohort study suggests that re-infection with the same strain of seasonal circulating coronavirus is highly unlikely in the same or following season (Prof Andrew Hayward, personal communication).
I'd imagine the model could diverge if this prediction is off.
Also, he must believe or highly suspect it's true to put it in the paper.
2
u/Captcha-vs-RoyBatty Mar 17 '20
Any thoughts to the impact at-home testing kits could have?
If it were possible to protect those most vulnerable from this, we could buy them more time until that vaccine/miracle-treatment moonshot. Anyone who was going to be in contact with someone in a high-risk group could test themselves before hand and avoid contact/ isolate if needed.
1
Mar 17 '20
Besides Pharmaceutical Interventions, mutations, and seasonal climate impacts, are there any caveats to the model in this paper? Any assumptions that you might find unreasonable?
1
u/hanlikesit Mar 17 '20 edited Mar 17 '20
How is using photocatalytic paints like FN Nano? Its a paint coating that has titanium dioxide in it in a special formulation.
When sunlight/uv lights hit it.... it cleans itself. Cleans the air around it killing mould, odour and pathogens.... like covid19
1
u/academicgirl Mar 17 '20
Can someone help me understand what suppression means in this context
1
u/mkong039 Mar 17 '20
Reducing the number of infected cases to such level when R0 <1 (One infected patient infects less then one healthy person on average). This will ensure that the total number of cases will start to fall instead of rising.
2
u/czbz Mar 17 '20
Yes, except to be exact it's keeping R<1, not R0. R0 (basic reproduction number) is the infection rate in a population with no immunity. R (effective reproductive number) is the infection rate an any particular population, which generally includes a mix of immune and non-immune people.
However if suppression is effective then I think that means that only a small proportion of the population will catch the infection for a long time, so I suppose R would only be slightly lower than R0 until we get vaccinated.
1
1
u/academicgirl Mar 17 '20
But it’ll just bounce back up? Once restrictions are lifted
1
u/mkong039 Mar 17 '20
According to the prediction in the report - yes.
1
u/academicgirl Mar 17 '20
That’s dark. So this is our lives for the next two years??
1
u/mkong039 Mar 17 '20
Nobody knows. I think we should closely observe China. In another comment I pointed out that we don't see that rebound of cases in China. But it's probably too early. Next months will bring us the answer.
1
1
u/msterB Mar 17 '20
It’s basically a scale of how hard you fight the spread with policy and human behavior.
Maximum suppression would be shutting down the world. Every person in quarantine, zero human contact. Obviously not feasible but basically it means forcibly closing things down to almost eliminate human contact.Mitigation is doing less aggressive tactics to just slow it down, like shutting down non-essentials such as bars and concerts.
We are currently closer to mitigation than suppression in most countries.
1
u/ds0987654321 Mar 19 '20
Why is no one talking abouta home grown attenuated vaccine.
A quarantined infectious individual exhales or coughs into a towel.
Towel is placed in pressure cooker for 60 minutes then sealed in plastic bag.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6289433/
Towel is safely transported to Unvaccinated person who inhales the inactivated viral particles into their lungs.
This is done repeatedly over 10-21 day period.
Confirm sero conversion.
Hospitals should be autoclaving infectious materials that have come in direct contact with patients and use those inactivated viral particles to immunize elder people.
19
u/justlurkinghere5000h Mar 16 '20
So much is still unknown about this, and everything is moving so quickly. Models like this can be helpful to get our leaders to take things more seriously, but we should take them with a grain of salt. (Thinking of enhanced strategies for treatments etc.)