I think we give “them” too much credit in terms of being able to plan and implement anything of that magnitude. Certainly the US, Russia, China, and likely others have biowar capabilities and I would expect that they’d have vaccines for the elite and their staff before any such biowar mechanism was unleashed, But I don’t see the US, Russia, and others planning a war against humanity vs each other.
The ones that I really wonder about are the Chinese with their newly built empty cities. Are they in place for survivors of WWIII to start over in? I even more wonder what is beneath those cities.