NOTE:
This headline (From @US_FDA) is very likely NOT Accurate
Why?
1) Antigen Tests Detect a part of Omicron that isnt mutated
2) What the study identified is not that rapid tests are less sensitive - but simply that Omicron is more infectious
1/
politico.com/news/2021/12/2…
This headline (From @US_FDA) is very likely NOT Accurate
Why?
1) Antigen Tests Detect a part of Omicron that isnt mutated
2) What the study identified is not that rapid tests are less sensitive - but simply that Omicron is more infectious
1/
politico.com/news/2021/12/2…
So what’s going on here?
When measured against a certain amount of virus, the tests perform equally well across all variants, including Omicron
2/
When measured against a certain amount of virus, the tests perform equally well across all variants, including Omicron
2/
But, when asked how well do tests detect Omicron given an amount of “infectivity” in cells, tests were less sensitive for Omicron v Delta
Importantly, the issue isn’t the test!
Instead It shows a difference in Omicron infectiousness - and thus impacts ALL tests (PCR too)
3/
Importantly, the issue isn’t the test!
Instead It shows a difference in Omicron infectiousness - and thus impacts ALL tests (PCR too)
3/
Given the same amount of Delta and Omicron virus, the tests were the same
Given the same amount of “infectivity” of Delta and Omicron, tests had more trouble detecting Omicron - BECAUSE there would have been LESS Omicron In the dish to detect in the first place.
4/
Given the same amount of “infectivity” of Delta and Omicron, tests had more trouble detecting Omicron - BECAUSE there would have been LESS Omicron In the dish to detect in the first place.
4/
So… this means ALL tests will have more trouble on day 1 (PCR and Rapid Test) - not just rapid antigen.
But will still detect on days 2,3,4,5,6, etc…
The tests performed with the live virus experiment were only done for rapid Ag, not PCR… so headline discusses rapid Ag
5/
But will still detect on days 2,3,4,5,6, etc…
The tests performed with the live virus experiment were only done for rapid Ag, not PCR… so headline discusses rapid Ag
5/
Why is this important?
It’s important for people to understand that ALL tests will falter on day 1. If you feel symptoms, regardless of the test type - ASSUME YOU ARE POSITIVE.
But also recognize that the tests will still detect Omicron but know they may fumble on day 1
6/
It’s important for people to understand that ALL tests will falter on day 1. If you feel symptoms, regardless of the test type - ASSUME YOU ARE POSITIVE.
But also recognize that the tests will still detect Omicron but know they may fumble on day 1
6/
It is also important because the FDA was exceedingly vague.
What regulatory agency puts out such a vague warning with offering no explanation or data
The cynical side of me says it’s Almost as if they want to reduce demand by telling ppl they aren’t working.
7/
What regulatory agency puts out such a vague warning with offering no explanation or data
The cynical side of me says it’s Almost as if they want to reduce demand by telling ppl they aren’t working.
7/
Not surprising, UK Gov put out an announcement that offers useful info about their evaluation of rapid tests for Omicron (vs FDA which gave the most vague/useless message)
What did UK Gov find?
NO impact on rapid test sensitivity for Omicron.
8/
assets.publishing.service.gov.uk/government/upl…
What did UK Gov find?
NO impact on rapid test sensitivity for Omicron.
8/
assets.publishing.service.gov.uk/government/upl…
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