Some Great news!!

Terrific news from ⁦ @AbbottNews⁩ and a MASSIVE step forward towards widescale cheap, simple, rapid tests. This is the type of test that not only will diagnose ppl - but can stop transmission chains.

What makes this different?
1/ https://abbott.mediaroom.com/2020-08-26-Abbotts-Fast-5-15-Minute-Easy-to-Use-COVID-19-Antigen-Test-Receives-FDA-Emergency-Use-Authorization-Mobile-App-Displays-Test-Results-to-Help-Our-Return-to-Daily-Life-Ramping-Production-to-50-Million-Tests-a-Month

This is a simple $5 #COVID19 test that requires no instrument. That means it can be produced in the millions and can actually be used - without being limited or bottlenecked by the availability of the instrument.

2/...

Because this is an antigen test - this test will detect people when they are most likely to be infectious but without remaining positive for long periods of time after infection. This can be a major benefit to prioritize containing the virus.

3/...

That this is an antigen test does mean that it will not have as high a sensitivity after the transmissible period ends - Abbott says 97% sensitive in the first 7 days from symptom onset - which is when transmission is most likely.

4/...

Additionally - the specificity is reported at over 98% which is good for this type of test (more on this below).

So this is all terrific news.

But what isn’t this test...?

5/...

This remains a test that is EUA approved for clinical use by healthcare practitioners in a CLIA or CLIA waived environment. It is not available at the moment to everyone but must still be ordered by a physician. So it is going to be limited and not over the counter...

6/...

It is currently only available for symptomatic individuals. This takes off the table the type of use that I and others have been calling for.

In short these tests cannot at the moment be used as the type of transmission blocking tests that will drive down outbreaks

7/...

So it cant currently be used at home nor for asymptomatic individuals - and so effectively, with the current EUA approval this test has - it simply wont be the test, right now, to create herd effects and rapidly drop population prevalence.

So why am I enthusiastic??

8/...

Because this is a $5 paper-strip type test that gives near immediate (15 minutes) accurate results at the time when we need to know most that someone is positive - when that person is likely to be transmitting virus.

9/...

So this isn’t necessarily the test that is now going to open up frequent testing at the population level & induce herd effects until a vaccine comes along.

But this a great start to get this type of test into use for evaluation to eventually get us where we need to be.

10/10

I said I’m come back to specificity. This is a good specificity, 98%. Of course not perfect, 2% of neg ppl may get a pos result - which is partly why it is approved for symptomatics only. But for widescale use, there is a simple way to get specificity higher.

11/...

To boost specificity we can package two or three different tests together. With each of 30 over the counter tests against the nucleocapsid protein, you have 5 confirmatory tests against the spike protein. Combined you get terrific specificity sufficient for widescale use.

Also some data on sens spec for the thread. https://twitter.com/michaelmina_lab/status/1298813718181171200

Also - this is a front of your nose nasal swab to be performed (at this point) observed with self collection. This is not the really deep nasopharyngeal swab. This is a great swab for home use, simple to perform on your own - once home use becomes available :)