I thought I had got away with it. Had the jab at 11 am, fine all day, went to bed and woke about 2 am with the worst headache I have ever experienced, a fever and my legs didn't work so had to crawl to the toiilet. Paracetamol got rid of the fever but nothing got rid of the headache and I just lay there until about 8 am when exhaustion got me to sleep and I slept until 3 pm. No injection pain though. This morning I feel totally fine. I will know better next time and take Paracetamol in advance, drink more water and keep a walking stick next to the bed.