Oh no, it's just go figure.
Manufacturers of vaccines have been using adjuvants since the 1920s. A common one has been alum. Partly it's recognizing it and trying different things and finding that it actually increases a person's immunity with a smaller dose. So in terms of the trade-offs, you actually need less virus to produce a vaccine that allows us to develop immunity and protection against it.
I don't know whether you can speak to how it was discovered, but they're constantly trying different things so we can actually improve immunity.There are other things that can improve immunity, which people do, but in a vaccine that's actually our best strategy.