As a Fellow of the Royal Society of Chemistry with a special interest in Analytical Metrology, method validation and the use of certified reference materials and proficiency testing I'm possibly better qualified to hold an opinion on this matter than most. I was part of the ISO Committee the wrote the ISO/IEC 17034 Standard that defines how reference materials to be used in ISO 17025 accredited labs are to be produced and used.
I don't have all the answers, but I do know that there is a lot of bad science and poor interpretation of data in the media. Prof David Speigelhalter I respect enormously, and he has started to question how SAGE and politicians are using data.
This is his latest column in the Times:
Sir David Spiegelhalter: When a politician says they follow the science, that’s when I start screaminghttps://www.thetimes.co.uk/article/...reToken=ddafe06be410ea8419f94a03e00d0e2fRemember, SAGE is not a proper scientific committee, it’s conclusions are not subject to rigorous peer review, so it is effectively politically window dressing.
Back to COVID 19 testing: almost all of the testing uses a technique called PCR, or polymerase Chain Reaction. It is complex, if you want to know more, read this:
https://en.wikipedia.org/wiki/Polymerase_chain_reactionPCR is a wonderful and powerful technique and when PCR arrived 25 or 30 years ago was widely expected to be "the" analytical tool that would bring clinical and food microbiology into the analytical world. It did not. Why?
The main reason is that PCR cannot differentiate between viable nucleic acid and fragments, the latter are of no diagnostic use whatsoever. A test that cannot distinguish between live and dead bacteria and viruses is of little use.
Despite this in recent months we have a significant growth in PCR COVID testing: why? Because it is seen as better than nothing: I’m not really convinced.
Much of this testing is done on samples collected at home by the public, so the sampling efficiency must be questionable. Many of those sampled may have had a non-clinically significant dose of the virus, which the body's immune system destroyed, leaving viral fragments. Remember, COVID is a respiratory corona virus and our immune system has faced these viruses for eons. Some of us have very well developed ability to deal with a low level corona virus infection, so have shrugged off low dose COVID infections.
Worse, PCR is NOT properly quantitative in the way most other analytical tests used in medicine are, so it isn't able to tell us how much live viral RNA is present.
I do wonder if any of the COVID tests and the sampling procedures meet the requirements of ISO 17025, or the Clinical equivalent, ISO 15189.
The UK Accreditation service, UKAS, has accredited two labs for the antibody test, and has 30 in the que, but make no mention of PCR.
https://www.ukas.com/news/first-accreditations-for-covid-19-testing/There is at least one COVID 19 PCR Proficiency Testing Scheme from LGC, which is an important step, but that test doesn’t appear to be able to determine if the analysis is of viable RNA or dead viral fragments.
I therefore question if any of the PCR COVID test protocols have been properly validated, I know Eurofins are one of the main testing contractors: they offer V2 Plasmid Controls, but it would be interesting to know if COVID PCR tests are in the scope of their ISO 17025 accreditation.
I take the view that the PCR COVID test is at best a screening test and thus making major decisions based on data from such a procedure is bad science. In my view only if someone tests PCR positive and has one or more COVID clinical symptoms and tests positive for antibodies should it be classified as a "case".
At the moment it seems that there has been no statistically significant increase in hospital admissions, and I do not expect there will be, the next 4 weeks will be crucial.
Based on all the evidence available to me I do not accept the 6 person group limit is justified in any scientific way.
All that being said, I accept that anyone over 65, with existing co-morbidities, as I have (Bronchiectasis), needs to take a bit more care, so we avoid public transport, meeting with groups of people we don’t know, only go to the supermarket once a week and so on. But it does not and will not stop me helping out at the Aircraft Collection once a week and it will not stop Caroline riding her horse and getting exercise out in the fields and woods around our village. If the NHS tells me that I should return to full lockdown I will take very selective notice of their advice.
In the end we all make choices and take risks and must accept the consequences. As said in a previous post above, we want to get the most out of the next 10 years and we are not going to let fear of a disease stop us.
