if you go into pub med, which is a pretty good source, it has stuff on the cardiac episodes and also the Large B cell lymphoma cancers that my BIL, his best friend, and now his next door neighbor all have been diagnosed with in the past year. My BIL had the shots and 3 boosters. I have now had 2 boosters and I am done. Steve refuses to get any more also but it is scary when they say Covid is surging again. What to do. Geez.