Know some have written about whether or not to have the flu jab and possible reactions. Had my on Saturday, 8am. By 7pm I felt so bad - headache, muscle pains, sore throat and runny nose. Happy to say that 48 hours later I'm back to what is 'normal' for me. Was worried I was going to proper sick again, but relieved I feel so much better. As someone said, I'd rather 48 hours than 10 days of being really ill.