1. Healthy young children have an effective death rate of zero.
2. Ordinary, healthy adults are at very low risk of having a serious, critical or fatal outcome. "Serious" is defined as "in hospital required." "Critical" is defined as "ICU/Intubated/extraordinary measures." Fatal is obvious.
3. Co-morbidities, or serious age (>65) dramatically raises the risk of bad outcomes -- by a factor of ten, twenty or even a hundred.
This virus primarily attacks the lungs. It causes other symptoms but the bad outcomes occur when you are essentially asphyxiated. Those who have compromised pulmonary capacity (e.g. persons with COPD, diabetes with complications, old people with seriously compromised physical output capacity, asthmatics, etc) are at much higher risk.
While we do not have accurate data, which is likely because our governments don't want to characterize this, or quite possibly because they haven't bothered to do the backwork to do so, we can draw some reasonable inferences.
1. This infection causes some damage to the oxygen/CO2 transport mechanism, centered in most cases around the lungs.
2. A healthy person, not an athlete but an ordinary healthy person, can typically sustain a range of 1 MET (sleeping or sitting quietly) to roughly 10 METS. Each MET is about 3.5 VO2 points, more or less. Thus, if you know your VO2Max you know, more or less, what your METS capacity is. (This relationship isn't exact, but the estimates you can get without a lab test are close enough for this purpose.)
3. Moderate exercise (e.g. walking at ~3 mph) requires somewhere around ~3-4 METS.
4. Vigorous exercise is typically defined as 6 METS or above.
5. Climbing Stairs has been shown to be somewhere between 8 and 9 METs, or materially into the vigorous exercise realm.
6. Many runners, even reasonably-elderly ones (e.g. myself) can radically exceed 6 METS. In my present (not peak) condition, which is down a couple of VO2 points from typical, I can sustain about 13 METS. Therefore 6 METS is not really all that impressive at all.
Incidentally, in a few months of effort you can go from a capacity of ~5 METS to quite close to 10.
People do it all the time; it's called Couch-to-5k and while it takes effort most people can accomplish that in ~3-4 months. You could start now, but I know damn well if you're on the couch now you won't, so I won't bother trying to urge you to fix that.
Now let's contemplate what all this means.
First, if you cannot climb stairs without becoming winded you're in quite a bit of trouble and it doesn't matter whether that's due to asthma, COPD or just generally poor physical condition. Presume that you get hit hard enough that this bug takes 5 METS out of your peak capacity at its worst. If you can only barely reach 6 you're at risk of death! Add some cardiac compromise and the risk goes up quite materially.
I have long harped on the "any size is beautiful" thing, or the "fix it with pills" deal when it comes to diabetes. That's flat-out bullcrap and now we're going to have hundreds of thousands -- or even a couple of million people find out why. None of that virtue-signalling garbage will do a thing for your capacity to move oxygen and CO2 and this virus attacks that ability. You either have the reserve capacity or you don't.
Don't means you're DEAD.
Further, ICU and similar medical interventions will only change a few of these outcomes. The reason is somewhat complex, but it hinges on the fact that the body has to fight off the virus before it kills you. There is only so much medicine can do, irrespective of how invasive, when it comes to oxygen exchange. You can't run 100% O2 down someone's windpipe, forced or otherwise, for more than a few hours; after a day or so that actually causes temporary lung oxygen transport damage, which of course is going to make a situation like this worse. The maximum concentration that can be tolerated indefinitely is about 50%, which is roughly double that in the atmosphere, and in addition mechanical ventilation is not as efficient as natural to start with. What this means is that while an ICU can give you some margin back, it's not much.
A rush on hospitals will likely kill more people by a wide margin than it saves. The reason is simple -- if you don't have the virus and rush the hospital thinking you do the odds of being exposed approach 100%. If you're "at risk" and rush the hospital, and 10% of those "at serious risk" wind up dying, then the hospital has to save one person for every person who rushes the place whether they get in or not. It's not at all hard to imagine a situation where this kills ten times as many people as would otherwise expire!
Further, if this gets into a NICU it will probably kill every premature infant in there. You need to think very carefully if you have a kid in there about the implications of this in that a failure to be completely effective while scrubbing in will hose every kid in there, and if hospitals aren't freaking about this well they had damn well better right now. Infants wind up in NICU specifically due to pulmonary compromise; that's the issue with premature infants. For obvious reasons those wee ones have no spare capacity to fight something like this off.
That, along with a general rush on hospitals, would be bad so let's not do that, eh? Panic will serve nobody and is likely to get a sizable number of people killed.
There are roughly 1.5 million in nursing homes. By definition if you're in a nursing home you are incapable of taking care of your basic daily needs on your own. This almost-always correlates with being unable to sustain any sort of material physical oxygen demand. All of these people are at very high risk.
There are about 16 million Americans with COPD, most of them as a result of smoking. With any stage of COPD you are at severe risk with this infection.
Then there are those with diabetes, mostly Type II. This amounts to almost ten percent of the US population, or around 30 million Americans. What's worse is that another 80 million+ have pre-diabetes, essentially all of those Type II. The risk here is less-clear. To the extent that these conditions are potentiated or accompanied by severe obesity, and it frequently is, the exact management status of the diabetes is not going to be anywhere near as important as the person's general capacity to process oxygen.
So can we put some numbers on this?
Yes, but we need a denominator, and there isn't an accurate one. The bad news is that given our offshoring and "globalism" insanity over the last 30+ years and the "necessary" re-arrangement of our households to accommodate that such that one person going to work is no longer possible for most families we have a huge problem, like it or not. As a result of YOUR greed, avarice and allowing the invasion of the lower end of our labor pool by unskilled illegal invaders and sending the medium-skilled jobs to China and India we no longer can keep the kids home and teach them there where they won't get the bug, bring it home and infect you or, much worse, grandma. Your kids are going to get it and you're odds-on to get this thing too over the next year or so in no small part for this very reason. The good news is that your children are very unlikely to be seriously harmed by it.
You (and especially Granny) -- not so much.
(By the way, give a big hug and wet virus-laden kiss to the Democrats, Republicans along with yourself and your friends for cheering onward this garbage. If you think this is the worst of such bugs, and thus the worst-case outcome, you're nuts -- this is a preview of what will come again, and next time has even odds to be worse than this one. Maybe we ought to cut that crap, along with the open borders garbage, out eh?)
Since that's a guess let's assume you get it, and try to figure out how bad your odds are in that instance.
For those who have a METS capability in excess of 10: You can climb stairs for an extended period of time, you can hike on moderate to severe trails without having to stop frequently (or at all), you can jog or run a 12 minute or better pace for an extended period of time (several miles) without having to stop or walk. Your odds are very low of needing even basic medical intervention (e.g. a doctor visit) and vanishingly small of having a severe, critical or fatal case (likely less than 1 in 1,000.) However, do not be surprised if the virus forces you to curtail your physical activity, perhaps by quite a lot. In other words you might have a really bad time of it but not hospital-grade bad. We're talking about odds of materially less than 1% for any medical intervention required of any sort, and under 0.1% for hospitalization or worse. BTW the good news is that virtually all healthy children from toddlers to the age of 10 or so fall into this category.
For those who have a METS capacity under 10: This includes anyone with unmanaged asthma, COPD, who cannot climb more than a few flights of stairs sequentially without being winded or forced to stop, etc -- your odds of NOT having a serious or worse outcome go down rapidly with decreasing METS capacity. If you have asthma make damn sure it's controlled; that's typically not an actual shortage of oxygen transport on a physiological basis, but rather from spasms and similar, and as such is unlikely to correlate, if controlled, with more-severe outcomes. If you have compounding cardiac involvement that also limits physical activity that is a severe negative on top of lung issues because the last thing your heart needs is trouble in getting oxygen. If you're incapable of even moderate exercise (that is, you can't sustain a walk for a few miles without becoming winded) you are at extremely high risk and should do everything you can to avoid exposure. Those with serious health conditions, especially immune system disorders or cardio-pulmonary function trouble may have odds as bad as 1 in 10 of getting their ticket punched -- or worse.
Unfortunately the odds of a vaccine being developed, tested, and manufactured before you contract the virus, that is, before the next 18 months to two years, approximates zero. Therefore there is nothing but bad news if you're severely compromised and can't do anything to fix it.
So with this all in mind I'll take some wild guesses here on mortality.
We're going to lose an additional 10-25% of the people in nursing homes beyond those that normally expire in a given year. This sounds nasty but it really isn't -- the median nursing home patient dies in about six months! In other words while this is going to make the news (as it certainly did at Kirkland) the difference between cacking right now and six months from now isn't really very significant. It will make for a hell of a lot of press and scare the bejeezus out of people but in terms of outcomes and economics it's not going to matter much.
The much larger impact is going to be on those people who have COPD and similar disorders. I will not be surprised at all if 20% of those people die within 12 months as a direct and indirect result of this virus and there is nothing that can be done about it as COPD is not only progressive there's no medically known way to reverse it. SE Florida has huge areas where Sunday mornings feature an enormous percentage of the patrons at various eateries sucking down carbs by the plate-full, most of them ridiculously obese and many of them are toting around oxygen cylinders. More than a few, astonishingly, drag said cylinder outside with them in the middle of their meal to have a cigarette! A huge percentage of those people are going to die when they get the virus and there's nothing that can be done about it.
If you're seriously compromised as a result of diabetes and/or severe obesity it's definitely worth getting the damned carbs out of your pie hole right now. Every bit of compromise you can get rid of in that regard, and every pound and point of insulin resistance or hypertension you can remove will help if you accomplish it prior to getting the virus. I know, I know, you can't give up the pasta, potatoes and cake, choosing green veggies, eggs, cheese and meat instead. This time it's not just the size of your ass, it's whether your ass survives that may be stake. Choose wisely because if 10% of those people die we're talking about a couple of million additional corpses. That will matter both in terms of public perception and economics.
If you're not into athletics taking up a severe training regime is likely counter-productive in that the last thing you want to do is get well into oxygen debt if you have a bug like this, especially if you have some sort of cardiac problem you're unaware of. However, moderate exercise, if you're not currently doing it, cannot hurt and may help if undertaken outdoors in clean air. Not only are there unlikely to be virus particles you can inhale there and nothing you can touch that has virus on it, but in addition even a couple of additional points of VO2Max provide you with a bit more margin when, not if, you get the virus.
Finally, there's luck. There apparently are two serotypes of this thing going around -- the older version, and then a second serotype that is "younger" and more virulent. What's not clear is whether you gain any cross-immunity from getting one before the other; if not then you definitely want the bad one first, since if you get the bad one while recovering from the less-bad you're already compromised and that raises the risk of very, very bad outcomes. On the other hand if one is partially protective you want the lesser one first because it may blunt the impact of the bad one. Right now there's no science on this, so take your coin and toss it; this is a pure luck of the draw thing right now.