I read at least a half-dozen articles on this story and they were all vague when referencing the mAb. I got the impression it possibly came from a batch that may have not passed standards (perhaps purity?) for human use, but that is only conjecture. None of the articles discussed why it couldn't be used on humans, who made the mAb. A few of the articles stated it "was the treatment given to Trump" but again, the reference was so vague the author probably meant mAb's in a general sense and not specifically the same one trump used. If it treats silver baboons, it should treat orange baboons as well, right?