But the wider questions that he had around this particular topic around, for example, what level of testing would be sufficient to provide people reassurance that it was a satisfactory alternative to vaccination, the answer to that question is it very much depends on the context and on the frequency of the testing, and that that situation can actually change as the situation we're dealing with evolves. So the frequency, for example, of our border worker testing has recently changed as a result of the changed risk profile that we are dealing with there.