Second Moderna shot I call Mad Dog. I woke up at one AM with chills, fever, muscle pain, bed drenched in perspiration. It reminded me of my H1N1 2012 experience. It lasted about two days, and a couple of doses of Tylenol helped when the symptoms surged. I know for sure I didn’t get the placebo.
That strong reaction to the 2nd shot is actually a good sign.
It’s indicating that the first shot trained your immune system to recognize the virus. Your antibodies identified the 2nd vaccine and attacked it. Now they will be ready if you ever contract the virus itself.