Why wouldn't it be fixable? And would there be a way you think to test if that's really the case? I have talked with some people who had like severe reactions

Why wouldn't it be fixable? And would there be a way you think to test if that's really the case? I have talked with some people who had like severe reactions to the drug who managed to get some kind of mitochondria testing and it would say stuff like "30% of the active sites are blocked on the mitochondria"