in reply to @elynnbish Yes, my hematologist was the doctor who ran multiple tests which concluded the subject diagnosis. In fact, he ran the test three times just to be certain that the lab results were correct. He advised me that if I get a serious infection, such as a sinus infection or pneumonia, I will have to have immunotherapy. I have been lucky so far, and admittedly take a lot of vitamin C as a precaution, knowing that this probably would not prevent an infection if I were exposed to something serious. I do plan to get the next Covid vaccine as a matter of principal because I do not want to get very sick and wind up in the hospital, which I think would be the worst place to be if I were truly sick. If you can get into see a good hematologist, he or she should be able to run multiple tests to confirm your son's diagnosis etc. I had no idea that the hematologist did this sort of thing, as I was seeing him for my anemia and low iron counts, which resulted in 2 iron infusions, which is another story altogether. As a sidebar, he is now requested more labs, including a LDH test that has been abnormal twice. His nurse sent me a note a couple of weeks ago telling me I had to have the test rerun because the doctor thinks that the abnormally high values are a "fluke." Whatever that means.
Best to you and your son
Good luck.