The conditions to qualify for an early vaccine seems to be quite broad. My wife discovered to her surprise that she had an "underlying health condition" when she got called up for her vaccine a few weeks ago. We weren't - and still aren't - aware of any health conditions!
We think it is simply because when she was pregnant a year or two ago she took some drugs that moderated her immune response. She hasn't taken the drugs since. Apparently it is just a matter of people's health records being searched in a pretty basic way - if you are flagged up as having been prescribed drug X/Y/Z etc (apparently regardless of when) then you are treated as having an underlying condition and get the call.
We think it is simply because when she was pregnant a year or two ago she took some drugs that moderated her immune response. She hasn't taken the drugs since. Apparently it is just a matter of people's health records being searched in a pretty basic way - if you are flagged up as having been prescribed drug X/Y/Z etc (apparently regardless of when) then you are treated as having an underlying condition and get the call.