Important piece on immediate-result paper tests for COVID. Too often, media describes them as "less accurate." Wrong framework! They're useful in detecting contagiousness—not mere presence of virus which can show up in PCRs for weeks. Exactly what we need. https://www.theatlantic.com/health/archive/2020/08/how-to-test-every-american-for-covid-19-every-day/615217/

PCR-tests can find tiniest remnants of the virus for a long, long time. It's like finding fingerprints and acting like the thief is still in the house! Remember all those scary, sensationalist stories about "re-infections"? Many were likely PCR picking up RNA remnants for months.

As an individual diagnostic test at a point in time, PCR's ability to find every last virus bit might be useful but as a public-health screening tool, what we want is mass, cheap, rapid turnaround (immediate!) *and* a signal only when it matters—high likelihood of infectiousness.

Just like masks, there is a misunderstanding of what rapid tests like this are good for. They're key usefulness is to protect *others* from the infectious person, which in turn protects everyone by creating a public good: a less-infectious world. Stop calling them less accurate.

Yep. Temperature checks are pandemic theater for the most part and given the substantial role of a/presymptomatic transmission, symptom checks are a band-aid, if that. Daily immediate screening tests like this would be *for real* useful for screening. https://twitter.com/jordanfrank/status/1294295174647091203

These are *NOT* mediocre though. Once we frame them correctly, THEY ARE BETTER for what we are trying to do. For public health purposes, PCR tests are mediocre. A positive signal that lasts for weeks (PCR) is not as useful; and they are expensive and slow. https://twitter.com/luke_fernandez/status/1294295139402149888