Decision to recommend against antibody test after vaccination is yet another poor decision.

If CDC/FDA willing to say that full vaccination = immunity, then there is no good reason to say antibody positivity after vaccination does not equal immunity

So on the positive side, if just getting a vaccine implies immunity per, then a positive response after a vaccine that is detectable by antibodies should imply that the person was vaccinated - thus protected.


But..on negative side - if someone fails to seroconvert to positive on EUA authorized Ab tests after vaccination... this would be crucial knowledge for someone to have and to talk to their doctor about.

FDA should be encouraging Ab testing post vaccine - esp serial measures

I understand that FDA is making a statement that these Ab tests should not be used to definitively assess immune protection.

But the decision to comment against Ab testing post vaccination will be a net negative to our understanding of immunity in the long run.

This is the type of data that we need a lot of data for. By pressing against Ab testing post vaccination, FDA is making it more difficult, not less, to measure the immunological correlates of protection that are so crucial for public health.

This is yet another reason why we desperately need a new pathway at FDA focused on considering public health separately from medical diagnostics.

We must move away from a medical centric response to a pandemic and towards a public health centric response.

For clarity: FDA’s thinking is that if ppl get an Ab test post-vax and it says positive, then they may take fewer precautions

(Good ‘ol paternalism from FDA again)

But it really doesn’t make sense in light of current CDC guidance.... essentially: If vax’d, no precautions needed
So as far as I can tell, if getting an Ab test after being fully vax’d, the only potential behavior change likely to take place (relative to current guidance) is one of being MORE careful – when the Ab test is negative.

If Ab test is pos post-vax, would behave as if vax’d!


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More from @michaelmina_lab

7 Jun
I wrote this 🧵 👇and appreciate the many comments so far.

I want to comment in a new 🧵 here on Why we should encourage Antibody testing for those who are interested.

Or at least not recommend against it, as our FDA is currently doing.

First - we do not yet have all the information about what exactly an Antibody titer specifically means post vaccine in terms of protection.

So making a binary assessment of protection, or lack of protection based on antibody titers at this moment isn’t necessarily wise

But just bc we don’t currently have all the correlates of protection worked out now, doesn’t mean we shouldn’t gather Ab information today for our future selves.

We are in the middle of a pandemic. Science is moving FAST! In 6 months we may wish we had our early Ab titers

Read 10 tweets
30 May
It’s hard not to feel complicit.

As high income nations squabble over whether to vaccinate the youngest and least vulnerable, much of the world has yet to vaccinate their absolute most vulnerable.

Global inequities run deep. But this is a particularly egregious one.
Again, these are optimization problems.

We should ask questions like: how many childhood doses are worth a single dose in a 70 year old in India.

Probably you need thousands of childhood doses to offer as much benefit as a single dose to a 70 year old.
Of course, these are not just simple public health decisions that need to be optimized - these are massive geopolitical (mis?)calculations that are above my pay grade.

That or just frank ethnocentric behavior.

Probably a bit of both.
Read 4 tweets
29 May
Rapid testing found 10% of the cases in Nova Scotia

IMPORTANTLY, that 10% was almost entirely ppl currently infectious and actually needing to isolate.

So the *relative effectiveness* of the rapid testing is much greater than 10%.…
Just to be clear: 10% of the *detected* cases. Of course there were many more cases that no test picked up.
“If they had waited until they developed symptoms to get a PCR test, and then waited another 24 hours until they got the PCR results, that’s at least two days where they might have been unknowingly spreading the virus.”
Read 5 tweets
28 May
We have vaccines. But it doesn’t mean we stop caring to see where the virus is and adapt quickly if and when outbreaks take off.

Rapid accessible tests are not just tests. They represent real time accessible information on the virus in and around us.…
The type of testing we will need in a well vaccinated population isn’t the frequent rapid testing I’ve called on for a year.

I don’t want us to remain in testing purgatory.

The landscape is changing and so too is the type of testing that will be useful...

We will now move into a type of testing that is more targeted.

Less about suppressing massive outbreaks and more about having the tools to respond *effectively* if and when they arise.

Tools that allow us to not have to close anything down - but test to stay open.

Read 9 tweets
27 May
This is one of the most rationally written papers yet on #rapidtests to keep society running, shops open, people dancing and curb transmission

It also demonstrates well the problems of using high sensitivity lab testing for public health screening.…
The paper shows 500 ppl who went to a concert and were rapid tested before hand.

They also received super high sensitivity molecular lab tests before as well - but the results arrived only after the event.

What they found was interesting.

First - no one turned up positive on the rapid test at the outset. So a strong evaluation of its ability to screen ppl out didn’t really happen. But that’s ok, we already know the test sensitivity.

What is much more interesting...

Read 13 tweets
26 May
To maximize vaccines to halt #COVID19 - look to immunity 🧵

When someone gets their first dose - they should be offered to take a fingerprick blood sample at same time

That should be tested for SARS-CoV-2 antibodies

If positive, then don’t come back for a second dose.

There is now abundant evidence that shows that people who have been infected have as good a response to their first dose vaccine as those in infected and w 2 doses.

A nice paper here discusses an approach based on knowledge of being infected in past

This was a great paper in @ScienceMagazine that demonstrated strong B and T cell responses following single dose vaccine that rivaled or was even better than a two dose vaccine schedule (when absent the prior infection)…
Read 7 tweets

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