mRNA technology has been researched for at least that long, which I assume is the research they're talking about. Most of that research wasn't on coronaviruses, but some of it was. As I'm aware, they determined SARS vaccines weren't worth it, because of bad side effects, limited function, and the general populace gained natural immunity on its own so the virus essentially evolved itself back into obscurity. So, yes, propaganda, but as usual, with that dash of magic ingredient, truth. Then they can point to the research and, tada, it's true.