Long ago, end of 2021, a few sane people with integrity at EMA, warned for "immune exhaustion" due to repetitive (same) antigen presentation with frequent boosters (and re-infections). Lots of studies exist from long ago that show that the epigenetic program of immune cells changes every time the same antigen is encountered. This makes sense because our immunity needs to have an inbuilt brake on autoimmunity. Yet it is also known that viruses like cytomegalovirus or EBV can exploit this "feature" and thus remain in our bodies forever. That doesn't bode well. Such virus can become carcinogenic or assisting cancer in other ways. Or like in the case of HIV it can lead to terminal disease in the longer term. But don't worry. Lots of new mRNA vaccines are being made now to deal with those opportunistic diseases and cancer that are possibly being triggered by the covid mRNA injections. It's gift that keeps on giving. If you are a Pfizer shareholder.