Professor Mary Keogan:

The Senator needs to consider one thing. We, in Ireland, built up our PCR capacity very quickly to a high level. A number of other countries are extremely challenged in their PCR capacity and, therefore, in the absence of being able to offer PCR are using antigen tests where they really would like to have a PCR. The fact that somebody is using them does not mean that it is their preferred option.

To be honest, one of the huge misconceptions is that if one is antigen negative, one is not infectious. Our data from the meat plant validation show that while overall there is 52% sensitivity, of those people who have been missed, over half of them have PCR positivity at a level that would correlate with infectiousness and being a risk. So it is not correct to say that if one is antigen negative, one is not infectious. In fact, having waded through all of these data, some extremely strongly positive people, who would almost certainly be culture positive, have come up negative on antigen tests.

To be honest, if we were starting a validation in the aviation sector then I doubt if we would improve on available PCR capacity, and we have abundant PCR capacity. In the same way as when clinical services come to me and ask about using point-of-care testing, I often look at point-of-care molecular testing that will give a much better outcome, rather than antigen testing.

We have become too polarised and too focused on antigen testing. As Dr. De Gascun said earlier, we need to be clear what is the question that we are asking because good diagnostics involves getting the best available test to answer the question that is being asked. Tests do not exist in a vacuum or tests do not have a role in a vacuum. We have got to define what is the question, what do we want to achieve, how do we best achieve that and then look to a validation study of the best and most likely to work solutions.