Here is the thing... They can't "release" anything because they can't "control" the release of a virus. So they have to find a better way to do it- that way they aren't accidentally sacrificing themselves, their own families, and/or children and others they need to continue life on their terms. They may want you to THINK it's a virus... But nope. It'll be something else entirely and it'll get everyone paranoid enough to sit in their house, not leave, and die thinking someone is coming to save them with some "miracle cure" that isn't coming.