Here is what we do know, as of this writing, learned the hard way as the epidemic sickens and kills people. It seems similar to, but not the same as, the 1918 "Spanish Flu" pandemic. We have not seen this dangerous a disease since then. It is a once-in-a-century event.
Covid-19 seems to be at least as contagious as, and perhaps more contagious than, the 1918 flu. It seems to have a similar death rate (the number who die compared to the number thought to be infected), which is somewhere around 10 to 20 times higher than ordinary influenzas. Those are seriously-dangerous characteristics.
There seems to be another unusual characteristic that combines with the other two to make Covid-19 a truly dangerous threat. It seems to be more generally spread by people showing no symptoms, than by people who are just getting sick and beginning to run a fever.
That makes all of us potential "Typhoid Mary" carriers of the disease. It also makes taking temperature rather useless as a screening tool to determine who might be infected, and who might not be. Without massively-available testing, one must presume that all other persons are contagious, which argues for using stricter levels of quarantine.
So far, it is thought that the Covid-19 virus is spread within the moisture droplets ejected by sneezing or coughing, or even by talking. 5 minutes talking spews the same droplet numbers and size distribution as one cough. A sneeze just spews a lot more. The Covid-19 virus does not seem to be able to remain airborne outside of those droplets, the way a chickenpox or measles virus does.
Masks vary in their effectiveness against particle sizes. It is hard to breathe through a mask that stops particles the size of a large bacterium. No mask stops a virus particle. But even a simple cloth bandana will stop most of the moisture droplets from coughing or sneezing, as does about 6 feet of space (the droplets quickly fall to the floor). See Figure 1 at end of article.
What that means is that the new CDC recommendation to wear masks in public is not to prevent the infection of the mask wearer, but to stop the mask wearer from infecting others. It would protect the wearer only when someone got right in their face to sneeze, cough, or talk at very close range. The 6 foot distance rule already stops that effect.
The recommendation to wear a mask is actually based on this uncomfortable reality: that many seemingly-well people are actually infected, just not showing symptoms, and are walking around spreading the disease. This "Typhoid Mary" effect is not common, but may well be the case with this particular virus.
As already indicated, a simple bandana will work. Leave the real surgical masks for the health professionals. They need them. We ordinary citizens do not. When you go to the store, wear a bandana or a home-made mask. That's all you need, to protect others. The 6 foot rule protects you.
And for Heaven's sake, quit panic-buying toilet paper and other supplies! There is plenty being made, and plenty in the supply chain, for everybody's needs. The shelves are bare because so many folks panicked and took far more than their share (their "share" being what they really need). Shame on you!
Predictions about this pandemic are still guesswork. The CDC figures show a peak of 100,000 or more deaths in about another month. Maybe a month or two after that, it will be more-or-less over, and we can safely re-open our lives and businesses. But that's a guess, and it will likely change. See Figure 2 at end of article.
Had we started with the quarantining a month or two sooner than we did, the death totals would have been lower, but the time to the end of this gets longer. Time spent shut down costs all of us money and jobs.
That is the inevitable tradeoff: lives versus money. And it is quite the serious effect, make no bones about that. Job losses are already beginning to resemble those of the Great Depression of the 1930's.
But almost all of your mothers and churches taught you to value lives over money, that valuing money over lives was evil! Think about that, when you vote. Not just next time, but from now on.
Figure 2 -- How Quarantining Works, and What It Does
The best numbers I have seen on Dr. Fauci’s curves and predictions, as of end-of-March, say that with “social distancing” quarantining in place, US deaths may accumulate to 100,000 to 240,000 people lost. That death rate trend should peak out somewhere in early May. Without the quarantining measures, something like 2 million deaths would be expected. Maybe more.
Just to “calibrate” the threat of this thing, the US lost 407,300 soldiers in WW2, for a 1939 population of 131 million. That’s 0.31% of the population dead from war.
With Covid-19 at a population of 325 million today, it is 0.03-0.07% of the population dead with quarantining, and something like about 0.6% of the population dead without quarantining. You don’t credibly compare this pandemic to yearly traffic deaths or the H1N1 epidemic. You compare it to the casualties of a major world war.
Based on the numbers published in the newspaper, the US death rate appears to be near 2% of known cases of infection. For Dr. Fauci’s predicted death accumulation numbers, that corresponds to something like 5 to 12 million accumulated known infections. That’s about 1.5-3.7% of the US population infected, and 0.03-0.07% of the population dying of it. These numbers are clouded by uncertainty, because without widespread testing, we cannot know the real number of infections.
Using the rough-estimate 2 million deaths for no quarantining, and the same 2% death rate of those infected, the accumulated infections would be about 100 million, which is 31% of the US population. Quarantining is thus very, very important, by about a factor of 10 on the total infections, and on total deaths. So, those who deny or ridicule the risk are dead wrong, if you will forgive my choice of words.
According to Wikipedia, the 1918 Spanish flu killed something like 1-6% of the world population. The same article gives these statistics for the US: about 28% of the population became infected, and about 1.7% of those infected died of it.
The death rate among those infected is quite comparable between Covid-19 and the 1918 flu. The number of expected Covid-19 infections is lower, probably because of our quarantining efforts, despite our delay getting started. The estimate of infections without quarantining is actually quite comparable to 1918.
The Covid-19 pandemic really is an event comparable to the 1918 flu pandemic. We have not seen such a thing in 102 years.
This is quite serious, so I reiterate the recommendations I gave above:
#1. Stay away from crowds and gatherings, and when you must go out, stay at least 6 feet apart (which is what protects you from infection, not any mask you might wear).
#2. If you must go out where 6 feet apart is not feasible, wear a bandana or home-made mask to protect others in case you are unknowingly contagious (save the real masks for the health care folks who need them).
Corollary: if you are sick in any way, DO NOT GO OUT.
#3. Stop panic-buying and hoarding supplies, there is no need for that.
#4. Watch what your public leaders do (not what they say) to judge whether they values lives over money, or not. Then stop re-electing those with the wrong priorities.