Mr. Chris O'Grady:

I will let Mr. Osman give detail of the verification of the tests and how to ensure the results cannot be manipulated. I believe the pushback against the antigen tests is related to the spin about their accuracy by comparison with PCR tests. Regarding the spin about antigen tests being only 60% as accurate as PCR tests, which I have read along with every member of the committee, the detail, while it might be available, is misinterpreted. It is being found that an antigen test and a PCR test cannot be compared. They are two different technologies looking for two different things. The antigen test is looking for protein of the virus whereas the PCR test is looking for the RNA of the virus. The analogy, which ironically is Professor Mina's, is that the PCR test looking for the RNA of the virus is like a detective looking for DNA at a crime scene. More often than not, the crime is over. A PCR test will continue to detect RNA of the virus after people have been infectious and contagious whereas the antigen test will be positive only when the viral load is high and, therefore, when somebody is transmitting the virus. While research shows 71 out of 1,000 people tested positive using PCR whereas only 43 in the same group tested positive using an antigen test – I apologise because the figures are not dead on – that is not to say the antigen test is 40% less accurate; it is to say that the antigen test is testing for contagiousness and for whether the individual's viral load is high enough to mean he or she is transmitting the disease and infecting people. The PCR test, while it has no problem detecting, is actually detecting pre-infectiousness and post-infectiousness. It is not that the antigen test is less accurate but that it is looking for something different. What I have described is the origin of the inaccurate spin.