Consider the following:
HCQ was fine for the initial "covid" strain. The warning from the traitors is consistently "it's going to get worse", "it's coming back with a vengeance", "it's mutating", etc. Translate that to a DIFFERENT strain that may have been created to be worse than the first. In that case, HCQ may not be enough. POTUS and co. may have been hit with that second strain, and that particular one needs Regeneron. POTUS had known this. Maybe that's the strain they had found in LA when they raided that warehouse, from which POTUS had arranged the manufacture of the drug to combat it.