I've had both shots of the Pfizer vaccine. The first shot caused a mildly sore arm about 2 hours afterwards which lasted until the following evening. Then around day 3 or 4 I felt super tired and needed a 10 hour "nap" during the day. It really floored me, like I've just done back to back all-nighters. With the second shot I surprisingly had zero discomfort in my arm. However like the first one, after a few days I felt really tired and needed a (much shorter) nap during the day. Other than that, no chills, no fever, no headache, no nausea.