Tolerating the Pandemic #3

In two previous posts, I discussed some ongoing processes that will help us tolerate the pandemic better, and an update 3 weeks after the first.

It's been two months, which is enough time for more progress to have happened.  There hasn't been enough, and some things have had less progress than I've hoped for, but we've also seen a bit more progress in other areas.  Let's stick with the same framework from before:  Testing, PPE/Supplies, Treatments, and Societal changes to reduce contact.

Testing

In PCR testing, a picture is worth a thousand words, such as this one taken from Johns Hopkins:

We've gone from 58k tests/day, through 145k tests/day, up to about 450k tests/day.  It took us about a month to triple and another two months to triple again.  That's good, but it's still not at the levels that the Harvard study recommend.  It is, however, about halfway there, and we can probably get to where we need to be in another five months if the federal and state governments fund it.  Unfortunately, the harvard number is probably excessively conservative.  Newer research suggests that testing may need to happen as often as weekly to effectively suppress transmission within a population;  we won't reach those levels for a lot longer.  (But we have other means of suppressing transmission, below).  The more testing and tracing the better -- every time we catch a case, we help prevent them from infecting more people, which drives down the effective reproductive rate.

Serum antibody tests are now out in force, and some of them, such as the Abbott test, are showing very high selectivity and specificity.  They're helping drive better understandings of how much of the population has been infected and clearing up earlier divergent hypotheses about this (answer: in most places, the numbers are at or under 5%, which means we're very far from any sort of herd immunity).  We're not yet to the point of understanding immunity and the tests well enough to trust them as immunity certificates, but it's getting closer.

Supplies

n95 masks:  3M claims to be ramping up from the previous 35m masks/month domestically to 95m masks/month, but this is on a timeline that may take until the end of 2020.  The current phase of expansion is only expected to start producing more masks about ... now.  There's still a general mask shortage, and some of the decontamination efforts are scaling back their claims a little (e.g., Battelle's decontamination system, which they hoped would allow 20 reuses per mask, is looking perhaps like it will handle three reuses).  There's still a lot of benefit there, and hospitals are finding ways to use other respirators, but we still need more.  By the end of the year we'll probably be close to what we need.

surgical masks:  I don't have data yet on the production rates of ASTM level 1 and 2 masks.  Will try to update;  there are some folks at CMU attempting to quantify this.  Regardless, you still can't buy them in the store, so that's at least one sign. :-)

Cloth masksEvidence continues to pile up for the effectiveness of widespread cloth mask wearing as a way to reduce the chances of transmitting the virus.  More on that below.

Treatment

Some success stories!  In the previous update, I just handwaved that Remdesivir was possibly maybe helpful.  It's now part of the standard of care, having been shown to reduce hospitalization time (but the reduction in mortality was not statistically significant).  But two months is enough time to run a lot of studies, and the UK's large RECOVERY study completed an analysis of the use of the steroid dexamethasone in severely-ill COVID-19 patients, finding that it could cut mortality in ventilated patients by up to 1/3.  It's not a silver bullet, and isn't appropriate for use in less seriously-ill patients or the earlier stages of the illness (it suppresses the immune system), but this is a fantastic treatment improvement that can cut the overall fatality rate.

There are continuing trials of other antivirals and treatments, but as before, these can take a long time.  It's still reasonable to expect a few more treatment improvements that will reduce the fatality rate, but hold on to your hats:  The huge reduction in fatalities from dexamethasone is unusual and not something we should expect to stumble upon monthly.

In vaccines, there are now three vaccines in phase-3 trials , and from all signs it seems there's reason to be optimistic that we may have a vaccine in limited production by the end of 2021.  If we're lucky, front-line workers may have something even earlier, but we're still looking at least a year, and possibly longer, before things start to make a difference.  But this remains impressively fast and hopeful-looking progress for a vaccine.

Societal Changes & Knowledge About Transmission

I've sneakily retitled this section, because part of the improvements we get are from being able to be more and more selective about what we close, reopen, or change, and understanding the dynamics of SARS-CoV-2 transmission helps us do those things better.

Some of the most hopeful news is the increasing piles of evidence that non-medical masks and staying outside are effective, low-cost interventions to reduce spread.  It's hard to do randomized trials where people don't know if they're wearing a mask, but the correlations remain strong, and events such as the recent protests (outdoors + most people masked) did not seem to result in case spikes, compared to other reopening-related events (indoor dining/bars) that have been traced to case spikes.

Delivery services have fully ramped up and wait times for, e.g., Instacart and Amazon Prime Now and other services are back near to baseline in many locations.

Business are struggling to figure out how to safely allow employees to come back to work, and this isn't going to be a fast change.  Guidelines for schools and daycares are unclear, but I'm hopeful that as we gain more evidence about the spread in children, an update in two months will note that we now have effective policies for how to resume these things (comparatively) safely.  We'll hopefully be able to learn from Japan's experience reopening their schools, though keeping in mind that mask wearing is much more normalized there and baseline transmission rates have been lower.

We're nowhere near being back to normal.  But we've made continued progress in knocking down the reproductive rate, and that will let us have better choices in balancing daily activities and risk.  Now, of course, it will be necessary to actually make good choices, but that's a different post...

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