>This whole notion that we can do designer genetic therapies is, I would say, uncertain According to Pfizer and Moderna, it's very certain: safe and effective. >Deaths are not unheard of in clinical trials, which test experimental treatments and sometimes involve very sick people. Clinical trials? When did they start doing those? >any death during a gene therapy trial is an opportunity for the field to have a reckoning. But when you have millions of deaths, not so much.