First I think it’s great that they are using rapid tests for asymptomatic screening! This absolutely needs to happen - particularly as evidence builds that transmission peaks before symptom onset.
So that is great!
2/
Also, for those in the US - know that UK is purchasing their rapid tests from a California based company!! Shipping 1 million tests to the UK for mass rapid test screening.
Wouldn’t it be nice if Americans could also reap the benefits of this American innovation... :/
3/
What I am not aligned on is the decision not to offer these at home.
The rollout of these by soldiers and others increases the program costs dramatically, which leads to a lot of people feeling that this is not the best use of funds.
It also leads to other issues...
4/
Besides excessive cost of having the simple rapid tests be administered by someone else, it increases disparity in access to the test.
The moment someone has to go out of their way, this dramatically cuts down on access... further disenfranchising the disenfranchised
5/
It also greatly limits frequency with which these tests can be used! For a fraction of the cost, the tests could be delivered to homes via postal service and people could use them 1x-2x /wk. Access would be equitable and effectiveness greatly increased!!! And cost decreased
6/
To sum...
Very excited to see this program being out to use.
But would really like to see it be more distributed. It’s OK to put the PUBLIC back into public health! People can do this on their own!
(One more item about the article...)
7/
The article 👆says these tests miss up to 50% of positive people.
These people are no longer infectious! We must stop comparing Antigen tests to PCR.
The tests detect >90% of PCR positive people who are currently infectious! Perhaps >95%.
The concern is outdated.
8/8
Finally - in the first tweet I said it’s not a clean pilot study bc other interventions are also ongoing. I didn’t mean to imply that those should not be happening. YES THEY SHOULD. I was simply preempting inevitable comments that it’s not the testing alone, etc.
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Ppl worry transmission could occur at Ct > 30 and thus missed by Ag test
Transmissibility is NOT BINARY
Possible at 34? Yes
Likely? No.
This graph helps place Cts in context!
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(If do not see the full graph above - please click on it)
Easy to forget Ct values are LOG scale
They place as much emphasis on an increase of 1000 viral particles as they do an increase of 1,000,000,000!!
2/
But when we change from a Ct scale to a scale that shows the number of viruses withouth "zooming in" on the low end, we see just how stark a different 20-25 is versus 30-35.
3/
The vaccine is not necessarily a more trusted source of immunity. Both an infection AND a vaccine are likely to induce good immune responses. All of the information we have suggests that immunity to infection for this virus is... well... as expected
1/
@DrEricDing@VirusesImmunity@PeterHotez However, to the questioners point, we are hoping the vaccines will induce potent and long lasting immunity. The vaccines are designed specifically to direct our immune response to look in the right spot - vs searching all over the virus...
2/
@DrEricDing@VirusesImmunity@PeterHotez The leading vaccines are all designed to induce, primarily, an antibody response that specifically blocks virus entry. To do this, they display a piece of the spike protein - the key to unlock entry into the cell.
3/
Right... lets keep focusing on PCR lab based medical testing for a public health war
A public health test with a:
-24 hour delay is just OK
-48 hour delay really losing its use
-72 hour delay almost irrelevant for transmission
-96 hour delay - waste
68,671 cases
Pop: 885,000
HIGH test +ve %; i.e. not nearly enough testing
I'd be surprised if catching >1 in 5 cases
If so, does 68,671 => 343,000 cases?
And if so... 39% infected...is SD nearing Herd Immunity?
Should serosurvey much of SD to understand if so.
Note: It's tough to know what the true detection rate is. Is it 1 in 2, 1 in 5, 1 in 8 detected?
We don't know for sure.
Either way... SD has a LOT of it's pop infected.
Since it's one of highest per capita states, will be imprtnt to monitor this state
And no - I am NOT suggesting herd immunity as an option. I'm simply stating the numbers up there and suggesting that we monitor to better understand what has and what will happen.