Don't get me wrong, I understand why the elderly are being prioritised here. It's just that the first recipient of the vaccine is symbolic and their identity will be remembered. Choosing someone who has a significantly higher risk of death by natural causes at any given moment than a much younger person just seems like a bit of a risk to public trust in the vaccine, should that happen (and again, I sincerely hope it doesn't).
Erm...best not tell the anti-vaxxers about this...
https://www.bbc.co.uk/news/uk-england-coventry-warwickshire-57234741