The purpose of biological war today would be to kill billions of people.
(Why would government scientists be hacking the viruses? Because they can, and because all the state knows is how to destroy.)
But maybe it’s very difficult to wage one. This is because the human immune system is pretty powerful.
What to do? Why, create a crisis that would serve as a pretext for mass vaccination whose purpose is to destroy natural immunity.
The next virus that comes along will then have an easy time at causing mass death. In addition, you hook folks on permanent “booster shots” every 6 months or so. You both kill billions of people (to “save the planet”) and make billions of dollars in the process. Sweet!