Member Info for tomvisual

Registered on Cytiva website and received this generic info
https://www.cytivalifesciences.com/en/gb/detection-of-coronavirus

PL75
The Novacyt (also invested in) PCR test has a lab test time of 90 minutes.
The Optigene LAMP test is 20 minutes.
The issues with lab tests as been discussed at length on this board. Someone posted yesterday that in the US people are queing for 15 hours for a test. That tells me the system testing presently set up does not meet the need. The political establishment need a mass PoC test.
Yesterdays post https://doi.org/10.1101/2020.06.22.20136309
outlines one opinion on what the scientific community require.
As mentioned previously, a significant point is that below 1e6 N or E RNA cp/ml there is no much infectious virus, so perhaps Sensitivity may not be such a crucial issue as I previously thought.
Interesting.

Not sure what the tweet was ....
But the information seems to be about the Harvard Report I posted earlier
https://doi.org/10.1101/2020.06.22.20136309
A critical point is that the requirements for surveillance testing are distinct from clinical testing.
This is not new information.
Professor Peto has been going on about more testing from the start
https://www.bmj.com/content/bmj/368/bmj.m1163.full.pdf
Prof Peto calling for 10M tests per day.
What the political establishment want is mass testing. A PoC test that meets the minimum MHRA Guidelines (see my previous posts) gives then this for screening purposes.
If Avacra supply a Rolls Royce solution and meet the upper MHRA guidelines its win win for everyone. Test good for mass screening and clinical testing.
If Avacta supply a Ferrari solution and meet the lower MHRA Guidelines its still win win. The test is still good for mass screening. Clinical testing would additionally need to be backed by a PCR test.
The important concept is to address covid 19 pandemic, not to be fixated on numbers.
What does the scientific community want and what does the political establishment require?
The paper at https://doi.org/10.1101/2020.06.22.20136309
highlights opinion from the scientific community.
I did raise this in my previous posts and said a Ferrari solution is acceptable for me.
Its miles better than what we have at the moment.
Remember Sona and BD do not meet the upper MHRA Guidelines.
Test, test, test

Wiggly agreed.
Resistance at 10day SMA level on my chart

From the Harvard info, for surveillance testing looks like the MHRA minimum requirement will suffice. What is need for mass surveillance testing is a PoC test!
For clinical testing:
Clinical diagnoses target symptomatic individuals, need high accuracy and sensitivity, and are not limited by cost. Because they focus on symptomatic individuals, those individuals can isolate such that a diagnosis delay does not lead to additional infections. In contrast, results from the surveillance testing of asymptomatic individuals need to be returned quickly, since even a single day diagnosis delay compromises the surveillance program’s effectiveness. Indeed, at least for viruses with infection kinetics similar to SARS-CoV-2, we find that speed of reporting is much more important than sensitivity, although more sensitive tests are nevertheless somewhat more effective.
Looks like test, test, test is and always has been the requirement. Hopefully, we are about to deliver the best LFT!

Link at https://doi.org/10.1101/2020.06.22.20136309
So a "Rolls Royce" solution may not be required!!
Happy to have one TODAY/tomorrow/within one week!

Hurst10..
Url to information?

https://www.theguardian.com/world/2020/jul/12/immunity-to-covid-19-could-be-lost-in-months-uk-study-suggests
The paper linked here has some interesting things to say about Sensitivity of tests with LOD of 1e3 and 1e5 cp/ml. A key sentence, on page 2 of the paper, is, "First, since filtered samples collected from patients displaying less than 1e6 N or E RNA cp/ml contain minimal or no measurable infectious virus [7, 8, 9], either class of test should detect individuals who are currently infectious."

Doggy100
Interesting comment in the medical press article, "Wealthy countries have made the choice to pay more for testing to avoid a higher rate of false negatives. For most of the world, the expense means there is no choice, and the consequence is little or no testing.".
Still, if Avacta/Cytiva achieve the S & S of the High Performance Test in Dr Alastair Smith's table, then, at 2% Prevalence, NPV is 99.9%,which seems a very good result that, practically, could be used to declare someone uninfected. The PPV of the High Performance Test is a bit low, so if someone tested positive, then, if a country had the money, a PCR test could be done, or, if there is not enough money, isolate for 2, or preferably 3, weeks.
Lets see what this week brings for S&S numbers!

Highlights of listening to Gerry Brandon:
* The detection kit requires the Affimers to be refreshed every month. Maybe that is a good result, compared to other tests that are one time use. On second thoughts, I am not sure whether the Affimers need refreshing after detecting Covid-19, as I could imagine the binding of Affimers to the spikes might not be reversible. Maybe, though, only a fraction of the Affimers in the test device get used for moderate Covid-19 levels in the sample and perhaps the electronics can tell when a new lot of Covid-19 arrives. Need a few more details.
* University of Aberdeen involved in the validation.
* Prototypes in September.

The Guardian article linked to below has a link to the pre-print of the Guy's and St Thomas' paper. It is a pre-print, but it looks unlikely there would be major revisions.
There has been a lot of less definitive evidence prior to this paper, but the Guy's and St Thomas' paper probably settles the issue, of how long immunity lasts, pretty much once and for all.
The emphasis for the short term is going to be very much on testing and therapies.
The folly of herd immunity, by infection of an unprotected population, approach is absolutely clear.
Immunity to Covid-19 could be lost in months, UK study suggests

https://www.theguardian.com/world/2020/jul/12/immunity-to-covid-19-could-be-lost-in-months-uk-study-suggests
Test, test, test

MHRA Guidelines at
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/895745/TPP_Point_of_Care_SARS-CoV-2_Detection_Tests.pdf
Googling 'Positive Percent Agreement' turned-up the following: https://www.google.co.uk/url?sa=t&source=web&rct=j&url=https://jmd.amjpathol.org/article/S1525-1578(16)30136-2/pdf%23:~:text%3DIn%2520the%2520absence%2520of%2520a,and%2520negative%2520percent%2520agreement%2520(NPA&ved=2ahUKEwjwyvqFwb7qAhXRSBUIHdkCCbEQFjABegQICxAH&usg=AOvVaw1utyh8t90frp6lxP0hz3tg

From the linked to paper:
Errors in measuring the sensitivity and specificity of a test will arise if the reference standard itself is not accurate, that is, does not have 100% sensitivity and specificity, respectively, and is commonly known as an imperfect reference standard bias. Evaluating a diagnostic test is particularly challenging when there is no recognized clinical reference standard test. In the absence of a perfect reference standard, performance of a test evaluated against an imperfect reference standard is expressed as positive percent agreement (PPA) (the proportion of individuals with the target condition by the imperfect reference standard who test positive) and negative percent agreement (NPA) (the proportion of individuals free of the target condition by imperfect reference standard who test negative). Both PPA and NPA are reported as percentages.
So, for a test assessed against a good reference standard:
* Sensitivity approximately equals Positive Percent Agreement.
* Specificity approximately equals Negative Percent Agreement.

No reference to prevalence!!!
Sona (96%,96%) meets MHRA acceptable requirement only.
BD (84%,100%) meets MHRA acceptable requirement only.
Test, test, test

Just a thought, if Klaus was working flat out for LFT optimisation, would he have bandwidth to be prepare and do a presentation ?
I would like to think not.
News must be close.

OlderandWiser..
AS mentioned mass testing may be at the 2% prevalence level.
30% prevalance was quoted by AS for health care workers. I was intrigued to find out what the MHRA requirement was against the most challenging case.
Now I/we know.
If we meet the MHRA "desireable" requirement which is well above the FDA requirement then we have a PoC test which is the best on the planet.
The Sona and BD tests do not meet the MHRA "desirable" requirement.
If we go for the Rolls Royce solution, now I know what is required. The "acceptable" MHRA requirement is a lot less stringent in terms of S&S.
Test, test, test

From MHRA Guidelines
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/895745/TPP_Point_of_Care_SARS-CoV-2_Detection_Tests.pdf

My spreadsheet indicates that desired PPA and NPA (Positive % Agreement and Negative % Agreement) implies for a prevalence of 30% (top level) a S & S of:
Sens 97.5%, Spec 98.75%.
If we meet these figures then we meet the MHRA "desireable" requirement specifications. Thats good enough for me.
Sona and BD tests do not meet MHRA PPA and NPA "desired" requirement ( for a prevalence of 30%).
The Sona test alone meets the MHRA PPA and NPA "acceptable" requirement (for a prevalence of 30%).
My Baseline targets have been set at the challenging 30% prevalence level.

How long did FDA approval take for the BD test?

is £5B not the total investment package by the UK Govt for a whole myriad of requirements/resources?
Requirements at
https://ted.europa.eu/udl?uri=TED:NOTICE:263375-2020:TEXT:EN:HTML

Section II.2.4)
Description of the procurement:
To manufacture diagnostic or therapeutic products for the purpose of research, experimentation, study, development or to establish commercial viability or to recover research and development costs.
Tender provision is £5M NOT £5B here!!!
Test, test, test

What time is the webinar in uk time?

First attempt thus time....
News imminent

Listening to Radio 4 Today at 6:24
Daivid Evans (joint CEO of Swissport and Collinson) seeking exemption from Govt to allow travellers to fly to UK from US.
He advised that passengers would require to take a PCR test (result 7-24 hours) before travel. The "gold standard" test is estimsted to cost £100-£170. Cost to be subsidised by airlines and hotels.
US to UK (alone) travel industry has a revenue of £4B to the UK economy!
As RK stated a high sensitivity LFT test is required to meet the airline international travel requirement! Rewards are massive!
Test, test, test