I am personally not having another jab after seeing how the flu jab has completely wrecked my girlfriends brother life – I can’t remember what the diagnosis is now but it’s gone through “It’s all in your head” to possible Guillain barre syndrome to whatever it is now, with him being unable to work and physically unable to do much activity at all. Also had Cateract problems resulting from the treatments and has had to have operations on both eyes.
However at the time he had the jab he was training hard, circuits, etc.
So if I were to have another jab, flu or covid, or whatever, I would certainly be resting for at least a week afterwards.
That also fits in with a documentary I saw ages ago about people with ‘chronic fatique syndrome’ and most of them seem to have carried on with some intense exercise close to an illness which included a sore throat (virus…).