To get a jab I needed a letter from the trial saying I could, a letter from my GP saying I could and a half hour debate with a sympathetic doctor at a vaccine walk-in centre. "Computer says no," is basically the situation unless you can come up with a suitable blame-sharing document set. The walk-in centre doctor came up with a solution - "we can give you a booster - that's Pfizer - then maybe, by the time you're due your second dose, we can have a statement from the JCVI saying it's alright."
Apparently, because the national guidance doesn't exist, the outcome varies from doctor to doctor, vaccine centre to centre. It also depends on the trialists willingness to lie to the walk-in centres, though with computerised records the window for lying has now gone for most trialists.
I don't regret joining the trial. I actually felt as if I was doing something useful. I do regret staying on it after the UK safety/efficacy phase was complete - I'd already done my bit for science then
If I'd just got rejabbed with AZ or Pfizer in the summer (before the trial vaccine records were uploaded to the NHS app) I wouldn't feel like I'd needlessly spoiled 6 months of my business and family life.
Trivial stuff compared to the global impact of covid. That doesn't stop me feeling childishly pissed off about it though - especially as it's really only an admin issue.