Eventually they'll telephone you - as a young man telephoned me this lunchtime. I confirmed I had had 2 jabs of A-Z, yes, in the U.K. and no, I didn't want a Pfizer booster. I explained that they should be more flexible. Then it was OH - so I had to explain yet again (OH ca't hear on the phone any more) about his horrible reaction so, no he wouldn't have a booster.
Would I like to speak to a clinician. No, thank you, what difference would that make?
On to 'flu jabs and how important they are.... I explained patiently (it wasn't his fault and I suspect that he'd rung some pretty vehement anti-vaxxers) that I had had this year's months ago and, in fact, that I had been having 'flu jabs for nigh on 30 years.
I can only assume that this is just some dept. following up on boosters and not connected to the NHS mainframe.