Second dose of Pfizer is kicking my ass. Got the shot yesterday and felt fine with just a sore arm, but the second I went to bed I got sick as hell. It felt like influenza 2.0... Chills, fever, severe back and neck pain, my head felt like it was splitting in two. Popped 600mg Ibuprofen and that helped a lot, but I'm hoping I don't get worse again in two hours' time.