Booster if unwell on the day?

I think the guidance is that if you are mildly unwell and without fever, then you should still attend.

Might be worth going along, explaining your symptoms to whomever is administering your vaccine and taking their advice.

I’ve just had my booster. A different vaccine from the previous two. I had no after affects from the previous two but felt dreadful after my booster. Took a day plus to feel better.
With your debilitating symptoms I would not go. Wait until you’re totally over it and go then. You have enough to contend with without possibly exacerbating the situation.

If you aren’t actually feeling sick and dizzy today I would go, as a mild illness that you have recovered from isn’t an exclusion factor.

We asked for advice when my grandson was unwell and was told if no temperature it’s alright to go along
I had a slight infection when I had mine done but no temperature and all was perfect

They took our temperature before we were allowed in so if yours is normal it should be fine.

If you are unwell enough to have a temperature, increased pulse and breathing or need to be mostly in bed, you shouldn't have a vaccination - any vaccination, any age. This is because your body/immune system is already fighting off an infection and it could make you much more unwell - or not be as effective. A vaccinator should not give it in those circumstances. If you are slightly off colour or have a mild cold not confining you to bed then it is ok to have/give it. If you have been sick then you should not be near others for 48 hours after the last bout of vomiting/diarrhoea. This is to protect others.

I had an odd sort of dizziness virus the week before the booster. It hadn't quite gone away in that I still had odd 'swoopy' moments but no fever or sickness so I went ahead and had the booster and flu jab. Absolutely no after effects.

I had a runny nose on the day of my booster. I looked it up online and it seemed to be OK to go ahead as I did not have a high temperature. I went ahead with it and had no after effects not even a sore arm but the cold did develop into quite a severe one.

Well I have been and had the booster. It is nearly 40 hours since I was last sick, and after spending most of yesterday in bed and not exerting myself today I felt ok. I answered all the questions truthfully, and yes, it does say you are ok to have it if you have only a mild fever( mine has gone).
I didn't appreciate the long cold wait, about 20 mins outside, and some people were really struggling by the time they had walked from the car park up a slight incline. Not ideal for elderly people, and today was booster appointments only, no walk- ins.
Nonetheless, I am grateful that the vaccines are freely available, so I am not really grumbling.