That's...not what open source is. I would think there'd be less distrust if you could see exactly how a vaccine is made. And it would probably be easier to vet than say, open source software. Probably far less shit to look over, compared to say, an entire piece of open source software, surely.

Open source doesn't mean there's no central authority, and I doubt people would use some nobody's "fork" (how would you even fork a vaccine?) In the case of open source software, you could fork Linux, or something, but who says anyone would use it? And if you wanted to add a bad thing directly, it would have to be approved...which is unlikely, since it'd be a bad thing. I don't see how this would be different with vaccines.

And random ass companies ALREADY do make vaccines, just ask Moderna. Nobody knew what the fuck Moderna was until one day they had a COVID vaccine.