NEW RESULTS:

Rapid Antigen tests work v well!

Not all are same - Some much better than others

This paper is a masterclass of how to study AND interpret the use of #COVID19 rapid antigen tests!

Best study IMO to date of how to think about these tests

medrxiv.org/cgi/content/sh…
The paper 👆by one of the leading groups in the world on #COVID19 testing @c_drosten.

The paper supports precisely what we have shown in our research for these tests to be used as powerful public health screening tools to slow/stop outbreaks

medrxiv.org/content/10.110…
The paper evaluates multiple antigen tests and finds a wide variety of specificities and analytical sensitivities

Drives home message that not all antigen tests are the same! These tests use antibodies to capture the virus and these will induce potentially major differences

3/
It finds that the rapid antigen tests - as expected - will detect people when they are infectious!

Goes into detail but ultimately finds that some of the leading rapid tests can detect down to small amount of virus (relative to how high virus grows)

4/
It explicitly does NOT compare sensitivity of rapid Ag to PCR test positives because @c_drosten knows what he is doing! Directly comparing antigen to RNA test needs extreme care and nuance - which thus far only few have figured out how to do appropriately. This does it well

5/
This paper also does not look at symptomatic vs asymptomatic use... But WHY??

Bc the test DOES NOT CARE about symptoms. Clinical medicine cares. A public health test for contagiousness ONLY CARES ABOUT VIRUS presence

I wish @US_FDA could understand this

6/
The paper also finds exceptional specificity (>99%) of the leading rapid antigen tests like the @AbbottNews PanBio (not available in US - sorry) which agrees in full with the Abbott BinaxNOW test amd other studies

THESE CAN BE APPROPRIATE AS PUBLIC HEALTH SCREENING TESTS

7/
there are false positives 1 in a few hundred. Repeat on same test cut it in half. And repeat on another test cut it by another 10-fold or more.

So we MUST create algorithms to couple rapid antigen tests together: test 1 screen and if pos, confirm w test 2.

8/
Or couple with new generation of molecular tests that will become available

PCR-like tests that are rapid and done at home - like @HomodeusInc and others. Screen daily with antigen test and IF pos, confirm with at-home (or at work/school/nursing home) rapid molecular test

9/
The tools exist & work!!! They are available around the world - but not allowed in US for screening (WTF, why!!??)

We can do this -we just need to approach this pandemic as one major public health problem and not a lot of individual medical problems!

Strategy Is needed!

10/10
Maybe most important line in the paper:

“Although many caveats remain, the point in the course of the first week of symptoms at which AgPOCT results turn negative may thus indicate the time at which infectivity resolves.”

YES exactly @c_drosten! Agree in full!

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More from @michaelmina_lab

16 Nov
VACCINES can work!

Another #COVID19 phase 3 vaccine trial reports awesome results. This time, an estimated 94% efficacy

95 COVID19 detected: only 5! in the vaccine group and 90 in the placebo

But like Pfizer results - need to take w caution... WHY?

1/

investors.modernatx.com/news-releases/…
First, the amazing efficacy from phase 3 at this point for both @moderna_tx and @pfizer vaccines - both mRNA vaccines - is EXCEEDINGLY ENCOURAGING.

These results show that these vaccines are eliciting the correct antibody bases responses to stop symptomatic infection!

2/
What I am worried about is the time scale of the trials thus far:

The leading vaccines are presenting the spike protein to the human immune system. This makes sense! Immunize against spike and stop virus entry into the cells.

3/
Read 13 tweets
15 Nov
My brother is an amazing soul.

When the pandemic started and schools shut down, kids in Saratoga Springs,NY who relied on free school lunches for food, lost those lunches.

He, with his rather small deli in upstate NY started making free sandwiches for the kids.

Now this... Image
And this was the message. Image
This 👆is how we work together as a society to pull through this pandemic. This is encouraging and hopeful and shows off the best that humans can be.
Read 5 tweets
15 Nov
@elonmusk Great question! It’s more complex question and depends on why the test is being used - ie: do you want to know if you are currently contagious/risky to others or if you have any remnants of RNA? The difference may sound trivial but it is massive

1/
@elonmusk If the question is "Am I currently infectious right now when the swab is collected" then on *most* instruments/labs, data suggests a Ct value somewhere around 30 or below is needed. (Different instruments/labs are different - but that's a decent generalization)...

2/
@elonmusk If the question is "Am I becoming infectious" then even if you have a high Ct value... say 38... then it's important to test again the next day. If you go to 28, then you better stay put, you're likely infectious for the next 5-8 days or so...

3/
Read 10 tweets
12 Nov
Today - I’m excited about not just antigen tests but introduction of at-home PCR-like tests like @HomodeusInc that are in works

These will serve so many purposes!

A major one is as gold-standard to confirm rapid antigen tests in the home/school/work w/out need for lab PCR

1/
These tests will bring the full power of a PCR lab into the home! Or School, or work, or small medical clinic

They won’t scale as high as antigen tests in terms of numbers, but it makes them optimal for them to serve, in part, as confirmatory tests for antigen tests

2/
False positives for example do happen (not frequently) in antigen tests. Confirming w a 2nd antigen test is one way forward

We want to be sure a +ve in a nursing home is true so a person is cohorted correctly (otherwise a potentially deadly mistake).

3/
Read 4 tweets
11 Nov
Moving in right direction to reverse outbreaks

Here's how:

At-home frequent rapid tests

10M/day ->

pool 2 ppl/test ->

20M ppl tested/day ->

Ea house tests 1x/wk ->

140M ppl tested/wk!! ->

Herd effects: R << 1 ->

RAPIDLY SLOWS SPREAD in US

1/

medtechdive.com/news/bidens-co…
This plan can work with only 10M paper strip antigen tests per day in whole of US

US Govn't can produce / fund these tests. Ship to participating households. 20 paper strip tests per household...

3 are different (but look same) and are for rapidly confirming positives.

2/
We do NOT need all people to "buy into" the program. These tests are used in private (think... next to toothbrush) and need only half of a community to decide to participate.

So if 50% of people don't want to - they don't need to. Not mandatory... the plan still works!

3/
Read 25 tweets
10 Nov
NEW on Rapid Tests!

Exceptional data that should help path to at-home highly accurate rapid tests

In over 860 samples tested w ⁦@AbbottNews⁩ BinaxNOW, only ONE was falsely positive! The Specificity was > 99.8%!

Why is this so important... and what else happened here

1/
First: here is the pre-print

medrxiv.org/content/10.110…

Which @apoorva_nyc covered briefly recently prior to the study release

nytimes.com/2020/10/15/hea…

2/
Second, we are so frequently talking about sensitivity bc no one wants to miss a case (will come back to this...) but what is equally or even more important when we consider frequent rapid antigen tests to suppress outbreaks with millions of them daily is SPECIFICTY

3/
Read 11 tweets

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