My first shot didn't affect me at all. Ii got my second shot Friday afternoon. I woke up Saturday morning and it knocked me in the dirt. The good thing is in the last 24 hours I have slept 20 hours. The 4 hours I was awake I had headaches (I never have headaches ever) and kind of dizzy. It is midnight now and I'm ok. I was hoping it would not affect me but that wasn't the case.