I am one who never had a hint of a reaction to vaccines and that includes flue and Shingrix vaccines. I had my first Pfeizer 3 weeks ago and did not have any side effect not even a sore injection area. I had my second Pfeizer on Thursday and came home with no reaction at all. Went to bed early at 10:30 and woke up a half hour later with the most vicious and intense muscle and bone pains and symptoms similar to a real nasty flue. Spent a horrible night with 1000 mg of Tylenol in me. Finally went to sleep at 5am. Woke up 2 hours later with no symptoms at all. Strangest thing ever.....