Post #1148: COVID trend to 5/17/2021, unfinished business

The number of new COVID-19 cases per day is now down 56% from the peak of the U.S. fourth wave.  As a whole, the U.S. is now well below 10 new cases / 100,000 / day.

Source for this and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 5/18/2021, from”  The NY Times U.S. tracking page may be found at Continue reading Post #1148: COVID trend to 5/17/2021, unfinished business

Post #1146: Yet more confusing advice from CDC

Let me start off by highlighting what I hate the most about yesterday’s announcement from the CDC regarding masks.

The CDC does not control whether or not masks are required.  The CDC cannot give you permission to take off your mask indoors.  

And yet, that’s precisely how the Director of the CDC made it sound.  She phrased it as if the CDC gave all fully-vaccinated Americans permission to take their masks off.  And that’s how all the news reporting reads.  All the headlines say that vaccinated people may now remove their masks in most settings.

That’s not true.

To be clear, the CDC issues medical guidance on this issue.  Only.  The CDC does not control whether or not masks are legally required.  The governors of the various states control the legal requirements on mask use. The CDC cannot give you permission to go maskless in public indoor spaces.  Only your state government can do that.  Or, possibly, your local government.  Or, beyond that, whether the owners of various public venues choose to require masks even if it is not legally mandated.

In Virginia, until the Governor modifies the most recent executive order addressing COVID-19, you are still required to wear a mask in any public indoor space, vaccinated or not.  For example, if you go grocery shopping in Virginia, you are required to wear a mask covering mouth and nose, unless you claim that some medical condition prevents you from doing so.

CDC didn’t even bother to mention this aspect of it.  And as a result, the announcement was absolutely misleading.  You have to go onto the CDC website to find the correct wording of the actual announcement.  It reads as follows, emphasis mine:

Fully vaccinated people can resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance.

Source:  CDC

To be clear, rolling back mask guidance and mask mandates is commonplace, as the pandemic ebbs.  This Washington Post article gives a nice summary of what’s happening internationally.

Other countries seem to be able to do that in a clear and unambiguous manner.  But here, in the U.S.A., that process has now devolved into yet more confusing and unhelpful information from the U.S. CDC.  To know the actual story, you have to dig it up on the CDC website and read the caveats, as above.

I’m not even going to get into the social engineering aspect of this.  Let’s hope the CDC made this decision based on objective criteria.  Because it surely seems to have been pitched primarily to give people an incentive to get vaccinated.

Let me try to restate this accurately.  Mask requirements are controlled by state governments, local governments, and by private enterprises.  The CDC now believes that risk are low enough that fully-vaccinated people no longer need masks when doing most common-place activities.   It has now given new guidance on this issue.  Whether or not you can take off your mask depends on the extent to which state and local governments, and various private entities, align their rules with this most recent guidance from the CDC.

Post #1117: William and Mary, another good day, the math of herd immunity.

Today’s test results were 1-for-1772.  Three days of census testing are highlighted in yellow below.  In short, they’ve tested three-quarters of campus enrollment and found one COVID-19 case.

Again, obviously good news.

This is a follow-up to my last post, and in this I try to explain why you might not want to, or be able to, relax the William and Mary COVID-19 hygiene rules just yet.  Despite this good news. Continue reading Post #1117: William and Mary, another good day, the math of herd immunity.

Post #1030: Magid N95 respirator, a flat-fold mask with excellent face seal

This is the followup to Post #1023, my latest N95 mask purchase.

After looking over what was routinely available, my most recent purchase of N95 masks was 10 of these foldable Magid N95s, from Amazon.  The reasoning was pretty much the same as for my last purchase.  These are certified for industrial use, they are not certified for medical use, and they are an odd, niche style.  It doesn’t seem like it would be worth anyone’s while to counterfeit them. Continue reading Post #1030: Magid N95 respirator, a flat-fold mask with excellent face seal

Post #1004: On N95 masks and razor blades

Masks for sale to the public, 2/11/2021 NY Times Article

Today’s NY Times has an article on small U.S. N95 mask manufacturing startups that are now failing.  The reporting is muddled, at best.  The good part is that they list several small U.S. manufacturers, many of which appear ready and able to sell NIOSH-certified N95s directly to consumers. Continue reading Post #1004: On N95 masks and razor blades

Post #987: All the masks I’ve ever loved.

That would make for a short post.

There are a handful N95 masks that I’ve tolerated over the course of the pandemic.

I figured I’d take a page or two to review those, with an eye on which ones you might be able to buy now.  Not a comprehensive review, but one with a certain amount of put-up-or-shut-up realism, as I’ve actually worn these during the pandemic.

Bottom line:  Of the N95-type masks I’ve worn, one is currently available through an industrial supply house, via what amounts to a loophole.  (3M appears to be restricting that to industrial use only, but this industrial supplier will sell to individuals.)  And one is readily available on Amazon, but only in lots of 50 (for $58).  FWIW, that one folds flat and is easy to send via U.S. mail.  The rest are either unavailable or unacceptable.

Continue reading Post #987: All the masks I’ve ever loved.

Post 980: The French ban the worst masks.

European policy regarding masks seems to remain months ahead of the U.S. 

In prior posts, I documented that Germany has been distributing FFP2 (N95-equivalent) masks to high-risk populations since 12/15/2020.  The obvious analogy for U.S. heath care policy would be for the Biden administration to offer N95s to the elderly via Medicare. 

And both the country of Austria and the state of Bavaria are requiring high-filtration masks in public places. Continue reading Post 980: The French ban the worst masks.

Post #977: “Wear an N95” goes mainstream

September 9, 2020




January 24, 2021.



Above:  Fraction of the population wearing masks when in public.  Source:  Carnegie Mellon University Delphi Group COVIDCast.

By this time, most U.S. residents seem to have gotten the memo about wearing masks.  And my reading of recent news coverage is that America now seems ready to up its game on masks.  And it’s about time.

If you’ll go to Google News and search for N95, you’ll now see a spectrum of articles on a) why you should wear an N95, b) where to get an N95, c) alternatives to an N95.   As well as articles telling you to wear two masks, if you can’t get an N95.  Or articles giving reasonably useful generic ratings of which masks are better than others.  Or introducing you to other high-filtration standards, such as the Korean KF94.

Among which is an op-ed in today’s Washington Post with the straightforward title:

Everyone should be wearing N95 masks now

The Washington Post op-ed itself is pretty good.  The comments below it are just pitiful.  Either that was a target of the Russian trolls, or Americans have a long was to go in terms of getting educated about masks.  I don’t think I’ve seen misinformation and disinformation so heavily concentrated in one place before.

In this post, I’m going to offer three bits of perspective on how far we’ve come on this issue of wearing N95 masks, and then summarize any new practical advice that I can glean from today’s  crop of articles.

In short:  We’ve gone from “you don’t need one, and you shouldn’t wear one”, and no federal leadership on the issue, to “you need one to avoid aerosols, you should find one wherever you can”.  And still no clear Federal leadership on the issue.  And still a hard time figuring out how to buy a true N95 mask.

This is an area where the Biden administration could make a real difference in ordinary citizen’s lives.  Reading those Washington Post comments, I’d say that pretty much everybody recognizes how hard it is for a citizen to buy an N95 mask and have confidence that it is the real article.   It’s not like that’s some secret.

So, anything from cleaning up the marketplace so that we could know what we are buying, to some sort of government-run certification program so we could know what we are buying, to outright provision of certified N95 masks.  Starting, as I’ve suggested earlier, with provision of N95s to the elderly via the Medicare program.


Continue reading Post #977: “Wear an N95” goes mainstream

Post #976: Simple projection to March 1, and herd immunity.

How close will the U.S. be to herd immunity for COVID-19, on March 1 2021?  Even with the significant uncertainty involved, it’s worth making a few simple projections of that.  If nothing else this will put the current vaccination effort into perspective.

Even under a rosy scenario where vaccine injections double from the current 1M/day, and new infections continue to fall, only about half the population will be immune to COVID-19 as of the start of March 2021.  That’s well below the 70% that was thought to be required for herd immunity under the original strains of COVID, let alone the higher percentage that will be required for the more infectious U.K. strain.

Why does March 1, 2021 matter?  If the U.S. COVID third wave truly has crested, our next test will come as the more-contagious U.K. variant becomes the dominant U.S. COVID strain.  That’s predicted to happen sometime in March 2021.  Near as I can tell, that prediction is based solely on the amount of time it took for that strain to become dominant in the London area.  So that amounts to a crude guess.  But, at present, that’s the only guess we’ve got.

And if that’s correct, then vaccinations should proceed as quickly as possible.  But under any plausible scenario, vaccination alone won’t prevent a fourth U.S. wave of COVID-19.  We really need to be thinking about what else we’re going to do — such as making N95 masks available to citizens — in addition to vaccinations.

Details follow.

Continue reading Post #976: Simple projection to March 1, and herd immunity.