I had the AZ and suffered a slight fever then a few days fatigue (I have an underlying contributory condition) and no more than that.
Of the twenty or so people I know have had it one other experienced similar after effects, the others nothing if note. Both my parents in their 80s also have had it with no Ill effects.
It's gone into so many arms in the UK that I think any serious issues would have been flagged up by now.