First shot no reaction other than fatigue after working out at gym next day, after that nothing, after 2nd Moderna shot I had chills, low grade fever of 100.5 fatigue and small headache for about 16 hours then completely went away, all are listed as possible after effects, my neighbor and his wife had same shots, she had the after effects I had, he had none, everyone is different. I feel much worse with common cold then I did with the after effects of vaccine and cold lasts much longer, even 24 hour virus is worse then the after effects for me.