Landmark report not because it's likely to be accurate, but it scared the UK (and perhaps the US) into action from the high mortality figures based on the latest Italian data.
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??
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.
Tyler Cowen had a great take calling out the tradeoff implied by this paper, raising the question of if a 18m total lockdown (the upper bound of the recommendation in this paper) is even a reasonable thing from a society/utilitarian perspective.
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.
The problem with the CFR is that it assumes that everybody can get the care they need.
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.
That seems way less dangerous to young people than I'm otherwise seeing reported, and this is the report that's apparently so extreme it got the UK and US to finally do something.
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.
Italy reported today that 99% of the COVID-19 deaths in Italy had a preexisting condition.
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 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.
Could be just what they had. I thought we all thought the IFR was higher, in which case the Central point of it all being urgent is perhaps understated you think?
Most infections never turn into "cases", which is why the IFR (Infection Fatality Rate) is a lot lower than the CFR (Case Fatality Rate). How much lower is very, very hard to say.
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.
I am wondering - coronavirus (the usual one) is associated with common cold; we don't have any vaccine against it nor do we actually understand the common cold itself; moreover, COVID-19 has a similar genomic packing as HIV/Ebola, two diseases we don't have vaccines for either. I am wondering if it is just wishful thinking we get a COVID-19 vaccine anytime soon (i.e. in the next decade). Are there any reasons to be optimistic?
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?
> 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
Flu's evolve and there's feedback from the behavior of the humans they infect. So if they make you feel like crap you are less likely to spread the infection. So that results in a less aggressive infection out competing a similar but more aggressive infection, doubly so since the immune system will like cross react between the two.
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.
From what i heard, non-lethal coronaviruses immunity (so not MERS-CoV, SRAS-CoV or SRAS-CoV2) is lasting 6 month to 2 years, with the reinfection seemingly giving longer immunity.
There is no guarantee that there ever will be vaccine that is effective. There will for sure be trials, we are all hoping on a positive outcome for one of those.
I really wonder what future historians will say about this hysteria and the economic damage it causes.
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.
Curious about which numbers do not hold. Can you tell specifically? - a news article tends to cite a lot of numbers - And given the situation, can you also mention the original sources?
Here's a scenario I'm curious about. Chickenpox parties for young and healthy people who are then isolated. Use heavy suppression to make sure there are ventilators available for them should they be needed.
My gut feeling is that this could create herd immunity at small cost.
Natural spread is way inferior to artificial spread. By doing it artificially you can control exactly who gets it, can monitor them more easily, and can prevent the vulnerable from getting it. And you can very precisely control the rate of spread.
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.
If you don't sign you are to practice social distancing for a year meaning you will be excluded from most of society. How's that for an incentive? You see that is what the article proposes everyone should do.
Assuming they know they’re vulnerable they presumably wouldn’t go to these parties. However that’s quite an assumption, particularly among young people.
Because shutting down the economy will kill people, too. It will also decrease quality of life for everyone, and disrupt families, communities, cities and countries.
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.
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??