What a depressing, callous analogy. You are comparing the IP of an entertainment product to a drug of significant consequence to the health of citizens throughout the world. Well done.
And yet, we generally agree on some baseline human standards. Sure, maybe you can find examples of people who would think this is morally reasonable, but I would guess they are a pretty extreme minority.
I'm very obviously not a lawyer nor lawmaker, but I'm under the impression that anything can be classified as an act of war as long as another country is willing to treat it as such, and other superpowers/blocs are willing to sign off on this assessment, and back it militarily and through sanctions/incentives.
(Though this would all probably swept aside as soon as somebody reverse engineers the vaccine.)
What law was broken? Its like saying HBO breaks a law by having their shows exclusive to their subscriber base.