About 4 hours (7:00 pm). after the shot, I developed hives. They gradually increased until they were everywhere except my feet and my head. They went away about 5:00 am the next morning. However, they returned the next evening (same places) and then the second round also went away about 7:00 the next morning. This time, they didn’t return. My question is whether or not I should get a flu shot next year.