I have seen some really horrible gadolinium side effects from those MRI things, but I am unaware of any Covid studies.
I would be interested in seeing the pre-injected fluid stuff subjected to a magnetic field, mostly cause I expect it to do nothing at all.
I think it was mentioned earlier in the thread, proteins can generate magnetic fields using natural electric currents in the body, as an electromagnet. The vaccine solution itself would not be expected to be magnetic, as it merely contains the instructions for ribosomes to produce the proteins from amino acids.