🧵 When the goal is limiting transmission, timing of tests is everything

If you wait days for positive results before isolating, the time spent waiting must be factored in to the “effectiveness sensitivity” of a test.

Time is always ignored as a test metric. This is wrong

If people are infectious for 6 days and you have to wait 2 days for results, then for every 3 positive people detected, you miss the equivalent of an entire infection Bc the sensitivity while waiting is 0%.

This means the “effective sensitivity” cannot break 67%. But worse…

What’s particularly bad but also ignored is the **0% sensitivity** while awaiting a lab PCR result is for everyone - even people who are at absolute peak virus titers and immediate isolation is most important. For these people, rapid tests detect >95% - with immediate action

Continued failure of public health efforts and regulatory agencies to recognize time (& frequency) as metrics that are actually MORE important than molecular sensitivity for tests used to limit transmission speaks to our abysmal ability to focus on public health in a pandemic

If we look back in time to 2020, our US FDA preferred and prioritized PCR tests with a 7-10 day turnaround over tests with a 15 minute turnaround.

This meant that almost 100% of the tests used for most of 2020 had effectively 0% sensitive for infectious levels of virus.

To translate: FDA prioritized Lab tests that would identify near 0% of ppl in time to stop transmission over rapid tests that identify >90% of people in time to stop transmission.

One of the greatest failures of thinking by our agencies responsible for 100,000’s of deaths.


• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Michael Mina

Michael Mina Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @michaelmina_lab

24 Nov
This is honestly some of the most idiotic messaging I’ve seen this entire pandemic.

Come on Ireland - seriously?

Surely, You can do better.
Have rapid tests ready at home

If wake up symptomatic, use a rapid test. If pos, you have COVID. Done

If neg and think you may have COVID, check again later that day with a rapid test, or go get a PCR.

But if you have symptoms w COVID, rapid tests will detect vast majority
What is Fianna Fáil?
Read 4 tweets
21 Nov
🧵 I want to comment on what I was referring to👇

When we say “pandemic of the unvaccinated”, it is stigmatizing & inaccurate - this is a pandemic of a virus that is disproportionately afflicting unvaccinated

I urge us to consider root causes of why so many are unvaccinated

I have spent many years speaking w vaccine hesitant ppl and not once have I found someone choosing to not vaccinate out of spite

It is nearly always out of a combination of love and fear and confusion about who to trust.

In this pandemic, we have lost the trust of many…

The US has bungled the response to this virus in nearly every way pre-vax.

There have been many times when the public health decisions have had to be walked back. “We” have made many mistakes.

Yet we assume that everyone should auto-trust public health decisions

Read 9 tweets
20 Nov
🧵 When ppl give anecdotes about public health efforts not working - please proceed cautiously

It is rare that public health success makes headlines or goes viral Bc success in public health almost always represents the absence of anything interesting.

Bias is tough to spot

Imagine for example if a vax failure in a single person was the only times vaccines made headlines. We’d think they didn’t work. But this is why we have trials - to ensure that we put any Vax failures into proper perspective and measure rates of success vs failure

The same goes for anecdotes around tests, for example:

The White House Rose Garden outbreak made headlines and made everyone think that tests don’t work.

What was not discussed were the hundreds of WH events w no outbreaks owing exclusively in that WH to testing.

Read 4 tweets
15 Nov
I find it troubling that official guidance in US is to assume protection based on vaccine receipt, regardless of antibody status (even if completely Ab negative)..

meanwhile guidance says NOT to assume anything about our protection based on being antibody positive vs negative
Personally, I'd rather be antibody positive than antibody negative.

I'm having trouble understanding why evaluating Ab responses is so frowned upon here

This reminds me a bit of the early view of rapid tests... We don't know everything, so better to just know no information.
We know that if we are vaccinated and antibody positive, it's probably better than being vaccinated and antibody negative

We know that if we haven't been vaccinated, then if we are antibody positive, we have some immunity from an infection.

Why is this so bad to know?
Read 7 tweets
6 Nov
Confused about the new OSHA testing rules for unvaccinated?


A few options but if using Rapid Tests, the tests must be:

- Observed by the employer OR

- via a Certified Telehealth Proctored session (There are a few companies enabling this)


The rule applies to any companies with 100 or more people…

In these companies, employees must be vaccinated or test weekly.

A hefty fine of $14,000 can be placed upon companies out of compliance

So here are the testing options and pros/cons

First off, that $14k fine is PER individual out of compliance, and possibly per infraction (though Im not positive about the per infraction part).

Read 15 tweets
1 Nov
I truly dislike the term "Natural Immunity"

There is no such thing as artificial immunity

A vaccine drives a NATURAL immune response

The question is simply "how do you want to start building that immunity?" Through a risky infection or via a safe vaccine

Me? I choose vaccine.
Vaccines are one of the most holistic interventions we have in medicine and public health.

Vaccines utilize our natural evolved processes to provide our immune system with an Education.

They aren't a pill that kills pathogens by distributing to all our tissues...

Vaccines are perhaps the most natural thing we do in medicine to protect ppl from infections

Vaccines are small proteins that get taken up naturally by our immune cells.

The immune cells do exactly what they evolved to do naturally. Vaccines don't force anything.

Read 7 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Thank you for your support!

Follow Us on Twitter!