Day two. I received my first dose of the Pfizer COVID vaccine on Saturday morning. I had a bit of a headache that afternoon but otherwise, no side effects. The next day, Sunday, day two, I woke up with some aches and pains, but at my age, it’s hard to tell if those were new or normal. I forget. Others complain about a lot of pain in the arm where they got the shot, but not so much for me, at least nothing that a few painkillers couldn’t handle.