Nick Beeching

Yeah, my name is Nick Beeching and I'm an infectious disease consultant at the Royal Liverpool University Hospital.

And I also work as a senior lecturer at the Liverpool School of Tropical Medicine.

Well, first of all, you've got to have really good technically well-performing tests.

And we have those in the reference laboratory at Public Health England.

They were together with colleagues in Germany and elsewhere.

They're among the first in the world to develop a good reference test looking for the virus itself.

And that's PCR test.

We have developing reference tests for antibodies, again, in a central laboratory, but they take a bit longer to be sure they work properly.

And those are the gold standard tests against which everything else is measured, including kits that are being produced to be nearer the patient.

It's not just the test itself that matters.

It's actually how you take the sample.

And there's quite a lot of things that affect that.

But first of all, usually looking for the virus unless somebody's really ill on a ventilator, for example, you would take a swab from deep in the nose or right from the back of the throat.

And if that's not taken properly, then the test won't work.

So actually the sampling has to be done well.

And we usually combine samples from both the nose and the back of the throat.

And the other thing is when you take the test.

So people may not become positive the first week after they've been exposed.

And so it's also the timing of the test.

And all these things can affect the performance.