yeah, but sky sprays aren't nearly effective as they're made out to be, because achieving a concentration high enough to guarantee infection (for lack of a better word) is practically impossible. You'd be better off engineering a minor cold that naturally carries the dna into into cells and releasing it in a major airport, then sitting back and waiting. even then mutation and resistance are a thing.

short-term, filling the air might work in a densely filled, enclosed space, like a subway train or an er waiting room on a full moon, but it would take too long to achieve anything remotely viable in the open air. Long-term, it'd be impossible to maintain at any level high enough to achieve what you want, not to mention how do you protect yourself from your engineered bioweapon once it's out in the wild?