NWR new zero tolerance covid thread

Jeremy Caan said:
The Guardian article was from March 2021 and I was hoping there'd been more data since then.

But I agree there's comfort in the idea that high viral load carriers will be spotted by LFT, and that it's mostly lower risk low viral load infections that don't get flagged.
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Yes we have found them very accurate for positive cases and my experience makes me believe they work effectively as the person becomes more infectious, We have had three initial positives which were replicated with a PCR. It also picked up one positive that we never would identified as there were no symptoms at all. We only tested him as we were heading to a family dinner.

I believe the tests have been shown as pretty accurate now if used correctly. I’ll see if I can find the article.
 
This was the reference and certainly backs up my personal experience of when a person tests negative, then suddenly positive.


Published report here
www.dovepress.com

SARS-CoV-2 antigen rapid lateral flow test (LFT) sensitivity | CLEP

A formula for recalibrating relative performance statistics from LFT vs PCR validation studies to give likely absolute sensitivity of LFT. Click to read more.
www.dovepress.com www.dovepress.com


“There is a spectrum of infectious amounts of the Covid-19 virus and we show that LFTs are likely to detect cases 90-95% of the time when people are at their most infectious.’

He added: ‘The tests could achieve even 100% sensitivity when viral loads are at their peak and therefore catch nearly everyone who is currently a serious risk to public health.’”
 
was the reference and certainly backs up my personal experience of when a person tests negative, then suddenly positive.
Mike Humphreys said:

Published report here
www.dovepress.com

SARS-CoV-2 antigen rapid lateral flow test (LFT) sensitivity | CLEP

A formula for recalibrating relative performance statistics from LFT vs PCR validation studies to give likely absolute sensitivity of LFT. Click to read more.
www.dovepress.com www.dovepress.com


“There is a spectrum of infectious amounts of the Covid-19 virus and we show that LFTs are likely to detect cases 90-95% of the time when people are at their most infectious.’

He added: ‘The tests could achieve even 100% sensitivity when viral loads are at their peak and therefore catch nearly everyone who is currently a serious risk to public health.’”
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Very interesting, Mike, thank you.

"on average we would expect an approximate absolute sensitivity of over 80% in testing for individuals shedding SARS-CoV-2 antigens."

Does this mean a 20% chance of a false negative?
 
According to the Telegraph AstraZeneca is preparing to release new research on the jab's impact on T-cell immunity which it says could continue after antibodies wane. The paper says the development could explain why European countries are suffering a surge in infections yet to strike the UK.
 
One thing I did notice in our recent family infection was that the first LFT I did showed the faintest of faint lines on the T (positive) line. I felt fine that day, but increasingly worse from then on. The line got stronger each day. But the LFT clearly picked up the infection albeit at a very low level. By that point though the rollercoaster has started to go down the slope...
 
Jeremy Caan said:
According to the Telegraph AstraZeneca is preparing to release new research on the jab's impact on T-cell immunity which it says could continue after antibodies wane. The paper says the development could explain why European countries are suffering a surge in infections yet to strike the UK.
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Really? That sounds strange given the data (that I'm sure I've seen!) published comparing the waning effectiveness of the different vaccines, suggesting that AZ is not as good as Pfizer?
 
Alex Lake said:
Really? That sounds strange given the data (that I'm sure I've seen!) published comparing the waning effectiveness of the different vaccines, suggesting that AZ is not as good as Pfizer?
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What I heard (Tim Spector video again) was that AZ is initially less effective than Pfizer, but AZ's effectiveness fades more slowly. But I'm not sure AZ has yet "overtaken" Pfizer for anyone yet.

All this must be the subject of ongoing research, and in any case I have decided any difference in effectiveness is not worth worrying about. It is relatively minor, and probably depends on many factors we are unaware of. Also, the question for most older people is now about the antibody response from AZ with Pfizer booster, and possibly an infection too.
 
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It may well be different elsewhere but here in London it seems that most think it's all over. Waitrose customers, who probably all listen to Radio 4, are a sainted exception but every time I venture forth these days I have to make considerable efforts to avoid absurd crowding in confined spaces. I only hope it doesn't come back to bite us.
 
Alex Lake said:
Really? That sounds strange given the data (that I'm sure I've seen!) published comparing the waning effectiveness of the different vaccines, suggesting that AZ is not as good as Pfizer?
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If effectiveness is measured by detectable antibodies, yes. I guess this might rather be measuring effectiveness against illness, regardless of detectable antibodies. We'll see.
 
FWIW, these are the results concerning fading immunity I was referring to (Pfizer immunity fading faster than AZ, but from a higher starting point). They are based on real-life performance of the two vaccines in the UK, rather than measuring antibody levels. In principle that seems like a better idea, but I guess it does raise issues about exactly how the comparisons are made.

covid.joinzoe.com

Is COVID vaccine protection fading?

Our latest analysis shows that protection from the Pfizer and AstraZeneca jabs can start to fade within six months.
covid.joinzoe.com covid.joinzoe.com

Also I presume the work is not published and peer-reviewed. I think it is a ZOE project philosophy to get any results out ASAP, which you can understand in the circumstances, but caution should be exercised in interpreting them.
 
A few random thoughts:

1) Interesting article in yesterday's FT commenting on the accuracy or otherwise of the UK's excess death stats. Article quoted some UK actuaries who believed the numbers significantly overstated the true excess deaths from covid because they relied on prior years for the baseline that weren't themselves adjusted for the ageing population.

2) I was shocked to see Germany's covid deaths now going past 100k. Given how much better germany did initially, the situation must be pretty bad there for them to be catching up so quickly.

3) It's still all about the vaccination rate which is both good news and frustrating at the same time. There's a noticeable correlation in germany between regions where vaccines are higher/lower and case rates lower/higher, respectively. Seriously, WTF is wrong with people?? Just get the effing jab already!!!

4) Fingers crossed that the UK's policy of pushing boosters and allowing the infections to remain at high levels as long as the NHS could cope may stand us in better stead over the next few months. However, we are certainly not in a position to say that it has worked yet. Looks to me like we'll all be getting 6 monthly boosters for the foreseeable future.
 
Steve Slatcher said:
FWIW, these are the results concerning fading immunity I was referring to (Pfizer immunity fading faster than AZ, but from a higher starting point). They are based on real-life performance of the two vaccines in the UK, rather than measuring antibody levels. In principle that seems like a better idea, but I guess it does raise issues about exactly how the comparisons are made.
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Another report here https://www.google.com/url?sa=t&rct..._disease.pdf&usg=AOvVaw07yWI10rgp1GnXfeR8QUr3
 
Dan Baillie said:
It's still all about the vaccination rate which is both good news and frustrating at the same time. There's a noticeable correlation in germany between regions where vaccines are higher/lower and case rates lower/higher, respectively. Seriously, WTF is wrong with people?? Just get the effing jab already!!!
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There's apparently a huge anti-vaccination movement in Germany which is not as amenable to persuasion as that in France has proved to be. I would somehow have expected it to be the other way around!
 
Thom Blach said:
There's apparently a huge anti-vaccination movement in Germany which is not as amenable to persuasion as that in France has proved to be. I would somehow have expected it to be the other way around!
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I try to be open to alternative views but these people really try my patience! Good news is that vaccination rates have picked up markedly in germany in the last week or so.
 
Some new scientific finding (if anyone interested):

AAAS

www.science.org www.science.org

This team use virus-like particle to check the influence of different mutations on virus growth.
So far most of people focus on S protein. Surely S protein is very important, but it's not the only factor in virus mutation and it also doesn't fully explain why certain variant (such as Delta) spreads so fast but other stains with similar S protein mutations do not.
Data here suggests that N protein is critical in virus genomic material packaging and some single mutation can increase viral load for 10-50 folds. It would be worthwhile to look into mutations in N protein in new variants.
 
Mark Carrington said:
A relative flew out on Tuesday for a fortnight. Yesterday afternoon I received a cheerful photo of Beaumont Chenin Hope Marguerite being imbibed. The mood will have soured overnight, in all likelihood.
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Presuably a whole bunch of such folk will rush back tomorrow to beat the deadline. Hope they can at least all get LFT & PCR testing (for immediacy and variant checking respectively) on their arrival (and not just 2 days later).
 
There’s been a slight hardening in the message from HMG of late. Test before you socialise etc.
I guess the new variant response is in this rap. But for me that’s all to the good.
 
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