You have to wait to be contacted I think. They have lists of volunteers - or that's what it sounded like.
I am a little puzzled though - not long ago the news was that blood tests were being curtailed sharply after today (I noted the date because I had one today) because of a shortage of vials/tubes. Doesn't quite equate unless the source of supplies is different.
It is great news, but ... as one of many people who have had blood tests cancelled because of a shortage of bottles, I was disappointed to see that this trial was prioritised higher than my immediate and practical need of a blood test.
Ellipsis - I have obviously been lucky because I had mine this morning, as scheduled. Does make me worry a bit in case it's more serious than they made out. :(