Condensing several reports, here’s my understanding of the mechanism. The vaccine hijacks the body’s immune response and forces it to concentrate on some Covid characteristics which probably don’t even appear in the newest variant. (Because the vaccine wiped out the Covid versions that had those characteristics.) If you had a total immune response of some arbitrary number, say, 10, each shot might sequester, say, 2 of that ten. When you’ve reprogrammed a certain amount then your immune system is exhausted and can’t fight things that it would ordinarily shrug off without you even knowing they were there. Thus, the sudden appearance in the young of previously rare cancers that only appeared in the elderly.
Vaccines "work" by presenting a piece of a virus or bacteria, a killed virus or bacteria, or an attenuated live virus to the immune system. The mRNA vaccines are a piece of the virus. The immune system thinks that a pathogen is invading and goes into action.
The first action is the inflammatory process, called the innate immune response. This causes the symptoms normally listed as vaccine side-effects like headache, fever, localized swelling, etc. Since there is not a real pathogen present, these symptoms clear up in a day or two. Some people don't have these symptoms at all.
The second action is the adaptive immune response, aka immunity. This is where pieces of the pathogen are taken into the lymph nodes for analysis. Over a two week period, cells in the lymph node study the pathogen pieces and become specialized T cells and B cells. B cells make antibodies.
There is no "reprogramming" of the immune system. Your immune system is capable of making specialized T cells, B cells, and antibodies against up to one quintillion different pathogens. Therefore, it does not matter how many strains of Covid you are vaccinated against--your immune system will never become exhausted. Decoding the variety of human antibodies. Quote: "Researchers genetically sequenced antibodies in people’s blood and estimated that the body may be able to make up to one quintillion unique antibodies." That's a lot of different antibodies.
The only thing that causes the immune system to "wear out" is age. The older you get, the more your immune function declines. Other factors that negatively affect immune function are diseases, cancer, and some pharmaceuticals.
There is no sudden appearance of new cancers. There has been a steady increase in cancer diagnoses since 2010, but no spike because of the pandemic. Are cancer rates really on the rise worldwide?
Cancer statistics, 2019. There were 1,762,450 new cases of cancer diagnosed in the US in 2019.
Cancer Data and Statistics. In 2020, there were 1,603,844 new cases of cancer reported. This may be lower than 2019 numbers because the pandemic impacted people's ability to get medical care and diagnoses.
There are no data for 2021 and 2022 since those numbers are still being analyzed.