Sigh. Phase IV trials are not part of the approval process; they follow formal FDA or EDA approval and noone is doubting they are important. Regarding risky: it is a well managed risk, and one that you simply cannot not take in the face of a debilitating condition, let alone a deadly pandemic. How do you propose new drugs can ever be introduced at all? And again: the Moderna and Pfizer (and also Janssen, somewhat) vaccines use a novel method of delivery, have been mass-rolled out. You seem to be saying that this should never have been done.