Not sure whether you watched/listened to it. I was a bit disappointed to be honest - not with Van Tam, but with the overall choice of questions. It was too geared towards "can I hug my Mum?" type stuff. There was even a question about Father Christmas. Not really scientific/quantitative enough for me, but I guess that's the general reflection of what viewers want, so fair enough.
Predictably the question of how long will the vaccine confer immunity was asked, to which the by now blindingly obvious answer of "we don't know" was given. I think most people are already aware of that.
The one question I did find totally relevant was whether certificates would be issued with the shots, as I know many places will be insisting on some proof of inoculation before they will let you through the door, in the future. But again he was somewhat ambivalent on the point. There would be a strict medical record kept, but he wasn't really sure on actual certification which could be carried around. Which again is an understandable response as he's not a government minister.