COVID vaccine makers are developing new boosters for a fall campaign. But some experts question the FDA's decision to tell companies to make shots against the BA.4/5 subvariants. "Are we trying to be too perfect and then costing us months as a result of that? You know, if we were starting over and all things were being equal and BA.1 and BA.4, 5 could be, you know, developed at equal pace, no question, BA.4, 5 is better.