I had the flu jab last Wednesday, no reaction, no pain. According to Google any reaction should happen almost immediately.
24 hours later at midnight ish on Thursday I started shaking with cold and burning up. Every night since then (4 nights) I have been freezing in bed even though the room is warm, my electric blanket and tons of snuggly duvets are on.
Shaking uncontrollably, even when sweating.
Last night was the worst yet - awake for 2 hours pouring with sweat and freezing.
According to nhs website reactions don't persist for days - around the site of the injection it is still rock hard and painful.
During the day am fine 