The latest Investing Matters Podcast episode featuring Jeremy Skillington, CEO of Poolbeg Pharma has just been released. Listen here.
London South East prides itself on its community spirit, and in order to keep the chat section problem free, we ask all members to follow these simple rules. In these rules, we refer to ourselves as "we", "us", "our". The user of the website is referred to as "you" and "your".
By posting on our share chat boards you are agreeing to the following:
The IP address of all posts is recorded to aid in enforcing these conditions. As a user you agree to any information you have entered being stored in a database. You agree that we have the right to remove, edit, move or close any topic or board at any time should we see fit. You agree that we have the right to remove any post without notice. You agree that we have the right to suspend your account without notice.
Please note some users may not behave properly and may post content that is misleading, untrue or offensive.
It is not possible for us to fully monitor all content all of the time but where we have actually received notice of any content that is potentially misleading, untrue, offensive, unlawful, infringes third party rights or is potentially in breach of these terms and conditions, then we will review such content, decide whether to remove it from this website and act accordingly.
Premium Members are members that have a premium subscription with London South East. You can subscribe here.
London South East does not endorse such members, and posts should not be construed as advice and represent the opinions of the authors, not those of London South East Ltd, or its affiliates.
Watching2 I fully agree there. The govt are clearly very worried about the impact of schools reopening and full predict a second wave with current sub par testing standards. If what we currently have includes swabs that tickle your brain and make you vom - kids aren't going to play ball. Hoping we have something available for 1Sep branded AVCT
https://www.bbc.co.uk/news/health-53638083
@Spike66 - Cytiva
@Chengdo - I think it's in clinical validation now across different territories. A week on wednesday is my current best guess........ but that is just a bit of pseudo informed fun - I don't know anything concrete
Ophidian
Ophidian
Spike :
“ At the time I think we just saw this as a lucky strike which provided added value but, actually, the blocker had become a pre-requisite.”
Indeed, I think most of us thought of nothing other than the therapeutic value of the announcement.
Imagine the trauma, I can remember getting my BCG and the rumours flying around about how bad it was and the pain, scarring etc etc. Now imagine getting your brains poked at on a daily basis. It won’t happen. They’ll probably initially go for a weekly slower test using saliva. Until the game changer turns up...
Chen dog I think it will be before the schools go back LfD
Is perfect kids
Atm kids are refusing or are throwing up
While taking the swab test
trumps next interview:
Guanidine thiocyanate have we tried injecting this into patients, that could work right! the scientists are amazed at how good I am at this stuff!
Thanks Ophidian..... could that tweaking be done by Cytiva on the test strip itself, or is it more likely that Avacta may have refined and then shipped a new batch of reagents off to Cytiva ?
Spike - typically something like Guanidine thiocyanate would be used to inactivate the virus and that has the property of changing the surface tension of water. As such, it would impact the way the sample wicks along the strip and hence probably require a little tweaking.
Ophidian
You could use a mechanical blocker, aka a plastic bag, each test comes with a bag, after testing insert test into bag, dog poo style, and seal, 3 days later the virus is dead (or however long we think now, put some alcohol gel in there and it's quicker) shouldn't be difficult to solve.
@Ophidian..... perhaps some evidence here to back up your theory. On 11th May Avacta issued an RNS announcing that their reagents had been shipped to Cytiva that day. Very shortly afterwards, on 15th May, they issued a follow-up RNS stating that they had done further work and had now found that some of these reagents carried blockers which would stop Covid-19 infections.
Given what we have discovered over the last few days about the importance of these blockers, I suspect that the moving of the goal posts may have happened around 11th May, probably causing something of a panic in Avacta HQ !! I can well imagine a call coming into AS on 12th May... ‘we see that you shipped the reagents yesterday....quicker than expected (!)... that’s a shame because we were about to tell you that they wouldn’t be considered for clinical validation unless they carry virus blockers.... did you check for that ?”. This has caused Avacta to hurriedly carry out further work and only then did they discover, thankfully, that some of their reagents carry the blocker. At the time I think we just saw this as a lucky strike which provided added value but, actually, the blocker had become a pre-requisite. Prof Richard Body has since spoken about how most tests submitted to Condor fell by the wayside because they did not carry the blocker. In Avacta’s case, however, we know that we reached clinical validation in CONDOR and elsewhere well after 15th May so it seems that LFT (and BAMS) must have satisfied all such minimum requirements. It may be the case however, with the added focus on the blocker, that AVCT have been carrying out further refinements...... hence why CONDOR and others had not yet started clinical validation ( as of 2 weeks ago). If your theory is correct we are probably well ahead of the game here.
As always some really interesting thoughts from Ophidian, which may explain the “delay”. I am a little confused, however, because the TPP templates from June and July already included a bio security requirement for an early viral deactivation step in the test process, so I’m not clear what additional step Ophidian is suggesting, and if there is a further requirement, why the TPP hasn’t been further updated to reflect it?
Apologies for any ignorance or criminal stupidity on my part! Hopefully this may go unanswered if we get an RNS in a few mins!
CO...
I still think an effective Sensitivity estimate is still required for assessing test effectiveness.
Supposing that the test correctly identifies 10,000 copies /ml for 100% of the time and assuming the purpose of the test is to identify people who are infectious, then the way that Sensitivity can be less than 100% is that, for periods, before the start and after the end of the period of greater than 10,000 copies / ml, an infected person is not showing enough copies/ml to be registered as positive by the test, but the infected person is still infectious and will be missed.
What is needed to estimate Sensitivity are reasonable numbers for: infectiousness versus copies / ml; and copies / ml versus time. I think there was a paper that had some guesses for these. The paper is, 'Test sensitivity is secondary to frequency and turnaround time for COVID-19 surveillance'
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325181/pdf/nihpp-2020.06.22.20136309.pdf
Looking at figs 1A and 1B in the paper mentioned, 10,000 copies per / ml looks a reasonable estimate of when people are infectious, but there perhaps will be circumstances - close proximity indoors for a long time - when 10,000 copies / ml will be an overestimate of when people are infectious, which will reduce the effective Sensitivity for a test that detects 100% at 10,000 copies / ml.
I was penning a few questions to the fda over their New Template. Will ask the FDA, if it is not in their documentation, is how many copies / ml is the FDA requiring the tests to operate with?
Test, test, test
From the Condor video noted on this site yesterday its clear that at least one company that put forward its test hadnt properly addressed biosecurity but no specific hint that this was avacta. Given avacta has been talking to the govmt for a long time I would hazard a guess it is another company. The 'delay' could be down to over optimism with regard to how much one could contract the normal timescales or could be that they are trying to eke out further improvements on an already great product - a ln extra week or two to achieve that would ultimately be appreciated if it results in the lft being the go to test in a wider range of situations.
Tomvisual - here you go. The updated HTML version has 10,000 copies/ml, original pdf version has 1,000.
Original version, pdf, 15 June 2020:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/895745/TPP_Point_of_Care_SARS-CoV-2_Detection_Tests.pdf
HTML version - updated 10 July 2020:
https://www.gov.uk/government/publications/how-tests-and-testing-kits-for-coronavirus-covid-19-work/target-product-profile-point-of-care-sars-cov-2-detection-tests
Any thoughts on how this affects the timeline?
Thank you Ophidan. Some common sense from. An expert.
CO ..
can you provide url to UK TPP?
Makes a lot of sense Ophidian - Why haven’t They haven’t worried about this sending saliva through the mail
Ophidian, thanks for sharing - very interesting thoughts... It had been on my mind as well that with Avacta and the UK govt in closer communication, there might be some behind the scenes to-ing and fro-ing on design specifications and acceptable standards before Avacta released the test for validation. This recent discussion on blocking viral transmission from saliva does seem to be a good candidate for the most recent nub of the matter...
Not sure how it would work though - if you block in a buffer solution, is there not a chance of impacting on the test’s operation? (Unless using Affimers that bind to different parts of the spike of course, and of course - we have these! Still could impact on sensitivity though?) Also why would this not be needed for buffed solutions from NP swabs? Another part of the threat from saliva would be with it being spilled outside of the test components and getting onto other surfaces which never see the buffer solution... maybe they are having to work out the right component design/test protocol to avoid that?
In other interesting news, did you notice that in the UK TPP for rapid tests, the “acceptable” limit for viral load LOD has shifted from 1000 copies/ml to 10000 copies/ml since we last discussed it? It seems from this and various other pointers that sensitivity is not the issue now, which if true would further support your suggestion here.
just my opinion @Canute40 I've not seen anything definitive published anywhere.
Ophidian
@Canute40 - I think it has always been a spit in a tube, add a buffer shake n pour type set up
Ophidian
Canute40 I think we have just affectionately named it spit on a stick
FN, apologies, I meant MHRA.
FN, I have went through each report on CONDOR website, and found none. Mostly about antibody, only one antigen. Cheers.
Girl up North how do you know they have not gone through CONDOR?