"We’re going to be evaluating whether an injection of our cells intravenously can tone down the immune system just enough so it gets rid of the virus but doesn’t destroy your lungs at the same time"
I don't know whether I've understood the concern correctly but is the issue the subject of the final clause, what the 'it' refers to? Grammatically the 'it' could refer to the injection or the immune system.
The way I read it was that the evaluation was whether an injection of cells would tone down the immune system just enough to get rid of the virus but not allowing the immune system to destroy the lungs at the same time.
I'm not sure if that's what you meant and I have no medical background
(20min delay)