Imperial College report on Covid-19 that led to the extreme measures in US
threadreaderapp.com
threadreaderapp.com
However, let's look at how the report underestimates the effectiveness of interventions:
Case isolation in the home: Reduces non-household contacts by 75% and assumes 70% of households comply : so only reduces non-household contacts by 52%
Voluntary home quarantine: Reduces community contacts by 75% but assumes only 50% of household complies.
Social Distancing: "Reduce contacts by 50% in workplaces, increase household contacts by 25% and reduce other contacts by 75%. Assume 75% compliance with policy."
Social distancing of entire population: "All households reduce contact outside household, school or workplace by 75%. School contact rates unchanged, workplace contact rates reduced by 25%. Household contact rates assumed to increase by 25%."
Closure of schools and universities: "Closure of all schools, 25% of universities remain open. Household contact rates for student families increase by 50% during closure. Contacts in the community increase by 25% during closure. "
25%, 50%, 75%... Where did they come up with these figures??
When numbers are too round, the good old "finger in the air"
I'm in a country with mandatory social distancing, and parents are still having school cricket and soccer matches in the local park. The parents are all clustered together watching.
They think their children are "immune".
"insufficient measures" - the term used after the pandemic.
https://marginalrevolution.com/marginalrevolution/2020/03/he...
Alternatively, let’s say we start off being really strict with shutdowns, quarantines, and social distancing. Super-strict, everything closed. For how long can we tolerate the bankruptcies, the unemployment, and the cabin fever? At what point do the small businesspeople, one way or another, violate the orders and resume some form of commercial activity? What about “mitigation fatigue“?
Again, I fear we might switch course and, again, end up with the worst of both worlds. We would take a big hit to gdp but not really stop the spread of the virus.
I also can imagine that we keep switching back and forth. The epidemic yoyo. Because in fact we find none of the scenarios tolerable. Because they are not.
1. We could forecast a projected cost to the global markets, vs. the number of lives saved, and put a price to each life saved. Every healthcare conversation has avoided doing this, so maybe this pandemic will force the conversation.
2. We shelter in place, take the hit to the market, and use the opportunity to learn a lot about our impact on the environment, ourselves, and how we can possibly change as societies to make things better for everybody.
Not only is the CFR lower than I had anticipated, but it made me realize that a hospital trip doesn't immediately imply intensive care.
For instance a 35 year old has 3.2% chance of going to hospital, and then 5% chance of ending up in the ICU when going to hospital.
Can I multiply these together to get 0.16% chance of ending up in the ICU once infected, or is that too simplistic :)
What with all the people who are obese, smoke heavily, have asthma, immune compromised, etc I would have assumed 0.16% of people find themselves in the ICU if they get a cold.
If you're healthy you (probably) don't have anything to worry about, but if you're diabetic, smoking, have hypertension or other normally manageable conditions, you're (maybe) at risk.
And to all the healthy people who seems to think they're immune. You probably won't die from it, but someone in your close family may very well die because you didn't take it seriously.
If the health system gets swamped by 50% of a country's population, then you basically have the same situation as they have in Italy.
We're just at the very beginning here in Denmark, the number of hospitalized people has roughly doubled every day for the past 3-4 days, and already hospitals are running out of masks and other essential equipment. Since the world is in lockdown, and everybody is fighting this, basic supplies are in short demand everywhere.
If that estimate is wrong, all of the numbers in the models would be wrong too. Strange that they tried a range of numbers for infectiousness but only one basically educated guess for IFR.
The current death rate of closed cases is 9%. I guess the expectation is that it falls once we develop a vaccine?
Also note that there's no strict definition for how to calculate the CFR, so you'll see conflicting numbers even for the same area/country.
Also, regarding herd immunity - we aren't immune against flu, is there any reason to think we could develop (long-term) immunity to COVID-19?
Spanish flu became less lethal in subsequent generations[1]. Helps with the survivability of the virus if it doesn't kill the host. So, the strains with less lethality win out.
We don't need to be immune for the situation to resolve. Simply co-evolving with the virus is sufficient
[1] https://demystifyingscience.com/blog/2020/3/4/patriarch-of-p...
Which is the case for COVID-19 vs original SARS (much more lethal). So we already have a "mild" version of SARS and it doesn't look good.
However with COVID19 the infection seems quite adept at spreading before the symptoms show, so there's going to be less of a feedback loop. Might even be the opposite since a serious infection means visiting the doctors office, in many cases more than once, and finally escalating to the emergency room. COVID19 seems especially adept at infecting nurses, doctors, ambulance drivers, and EMTs.
Its not surprising tbh.
1) 80% of Americans would get the disease That sounds scary (big number!!). But I'm getting tired of the constant reporting of each and every infection. What is really relevant is infections of at-risk groups. Most infections, nothing happens!
2) 8-15% of all Americans over 70 would die. Newsflash: Old people tend to die more often than young people. What is the all-cause i.e. normal mortality rate of the elderly. One number I saw cited: all-cause mortality of 83/84 yo's in the US ~7 percent. Case mortality rate i.e. with infection in Korea among 80+ yo's: 7.4 percent. What am I missing here? Are the reported covid mortality rates all normalized by all-cause mortality and they report only real "excess" deaths or are they lumping everything together? This would be so mind-numbingly stupid, I really hope I'm wrong about this!
3) 0.9% of them would die. That's the unconditional number, all age cohorts aggregated. Split them up and the number is clearly skewed by the large number of the elderly (and see 2 above). Now factor in that testing outside Korea, Taiwan etc. is really bad and focused on symptomatic cases. Common estimate of how high are the true numbers of infected is around one order of magnitude. Let's assume the official stats are off by a factor of ten. Let's further assume that young people (say, below 65) are "more social" or mobile than elderly and thus likelier to get infected. That means a) the undercount is dominated by younger people and b) the mortality rates are off by more than ten. At what point are we getting to mortality rates of common influenza?
4) There are basically two ways to die from the virus: a) immune system overwhelmed by virus or b) immune system overreacts. Younger, healthy people ( < 65 yo) seem to die more from b. Now look into who are the victims in this cohort and it turns out mostly medical professionals. Due to lack of preparation and equipment, those medical professionals are exposed to disproportionately higher or even extreme quantities of the virus. This seems consistent with b. Also, it means that the mortality rates of younger, healthy people is skewed by counting medical- and non-medical people together.
In sum, I think this is a total overreaction and panic that causes huge economic damage (which has a big human cost, in terms of lives lost, as well make no mistake) for what may turn out to be basically nothing.
What am I missing?
[EDIT: I'd prefer we focus on the at-risk groups (elderly and pre-existing conditions like obesity, cardiovascular diseases, diabetes, etc) instead of just blanket-everybody. Isolate the at-risk groups until vaccine and/or medication are developed and let everyone else basically develop herd immunity until then. Increase testing. And basically use this as a call for more general health measures, not just virus panic. The immune system depends on sleep, nutrition, mental health/hormone balance, etc. With the panic and the economic crash induced by it, all these factors are becoming negative instead of positive factors for most people now.]
The "herd immunity" approach is a dangerous gamble, as one of the big unknowns is "How long is the immunity after recovery from COVID-19" -- it can be anything between 0 (no immunity) and infinity (immunity for life). If acquired immunity holds for less than the time required for a vaccine to be widely available, "herd immunity" will quickly become a massacre. The first wave will knock off the medical system (even if somehow everyone over 60 is protected), ensuring that the second wave will be devastating.
I much rather prefer the South Korea/Singapore/Japan alternative to the UK one.
The race is to arrest the exponential curve, somehow, at any temporary cost, for if we don't we can't apply the working options for COVID-19 response from Japan, South Korea, and Singapore.
Can you tell me which exactly and indicate why?
My gut feeling is that this could create herd immunity at small cost.
I don't even know what the best course of action is, but there are trade-offs that a lot of people here seem to be ignoring.
We are all humans. All life is sacred.
Not exclude the statistic
> Chickenpox parties for young and healthy people who are then isolated.
Sign here to be given coronavirus and locked away for a month...
Natural spread is already outpacing likely ventilation requirements; we'll find out in a couple of weeks how badly.
It's a bit like saying a controlled burn can stop a forest fire - it's true, but it can easily get lost in the scale when you have an Australian or Californian situation and half the state is on fire.