The idea is that right now, this is only for people in really bad shape, but with advances and experience, this may become a more standard thing for people in less bad shape.

You first try the new, experimental drug on people who may die soon anyways, before you hand it out like smarties at the local drugstore.

Still have to get through that stage though with some good results to show for it, even if we suspect healthy bodies would handle it much better (although I wouldn't personally lose faith based on one instance)

Seven weeks with no sign of immune rejection is a good result here, for the very first attempt. It's largely what they would have been hoping for.