For me (I had the AZ one) I did feel worse than the normal Flu (every year)/Pneumonia (every 5 years) jabs (which always give me a very tender/achy arm for a few days), it made me exhausted after about 4 hours of having the jab, however after the first one I rather stupidly fought through the wave of exhaustion that hit me, and then it left me feeling really tired and exhausted the next morning (until about lunchtime), the second one I got the same exhaustion after about 4 hours so I went to have a kip for about an hour or so, and after I got up after that I was back to being normal and in fact was awake and healthy enough to go have a fight with the garden (and win, though I did end up with scratches and aches from gardening)