Bu US drugs standards, maybe, but given that they plan to sell billions of doses I think that's a pretty good price, especially because they already got plenty of grants and support during development.
Also if governments had said we want vaccines! Will pay $100 a head for an effective one I think private enterprise would have cranked out billions by now. Supply depends on how much you invest in production.
Maybe it's late with vaccines but the same principle applies to carbon. Set a $200 carbon price and private enterprise would go crazy with plans to take advantage.