I'm also not afraid of isolated viruses in desolate places. They have limited gene pool and no humans to practice with. It's incredibly unlikely that such virus

I'm also not afraid of isolated viruses in desolate places. They have limited gene pool and no humans to practice with. It's incredibly unlikely that such virus would randomly be very very good at targeting humans, but also very very bad at staying super sneaky when on a human host. The optimum strategy for virus is not to kill. It's to stay unnoticed and spread. And the best way to stay unnoticed is not to cause any symptoms ever. HIV is scary because it's not very good at staying unnoticed. But it's also very bad at spreading too. Same goes with anthrax and pretty much every other deadly virus/bacteria. They typically are optimized for other mammals and therefore they suck at both staying unnoticed and targeting humans.