It took 5 1/2 months for doctors to diagnose me with PML, and by the end of that time I was paralyzed down my entire left side. My understanding is that if I hadn't gotten diagnosed by 6 months, PML would probably have killed me, so I was extremely lucky to beat that deadline. This is the link to the article about my case from The Washington Post:
I would be eager to participate in any clinical trial that would have a possibility of improving my immune system. I have regained a reasonable level of function, by availing myself of every possible therapy (physical, occupational, speech, neuro-optometric), but I'm still vulnerable to many other diseases because of my lack of CD4 cells.
(I already participate in two NIH studies, one for PML and one for ICL, which are "natural history" studies that don't involve any treatment, since there are none to speak of. )
If the trials were in the Washington metro area, I would not hesitate to participate. At the moment, because the doctors are unsure if the Covid vaccine "took," I am barred from flying by doctor's orders, but that could change.
The things that would discourage me from participating are if I had to self-inject anything (despite all the procedures, including apheresis, I have undergone, I wouldn't want to have to self-administer any injections; I still can't watch my blood being drawn; it makes me queasy and light-headed.) An oral medication or some type of infusion would be fine.