Once again, this is hypothetical- only if this is not contained, i.e., what ever safety precautions to prevent this were broken.
Your lack of belief in how covert operations work shows a lack of history. I obviously have no secret knowledge about his, but even reading one or two historical accounts about intelligence services (and others) would prove you wrong
A lack of history? Don't make me laugh. Show me one historical example of such an operation as you suggest. While the CIA and others in the US government have often engaged in absurd and sometimes downright ridiculous plots, such as Operation Northwoods, Castro assassination attempts, and MKUltra, your suggested scenario is at least ten times more far fetched.
I'm not sure if I'm demonstrating a lack of belief in how covert operations work (whatever that means), but you sure are demonstrating a lack of common sense about what covert operations are even possible.
You don't think there's an easier way of manipulating domestic elections than sneaking into a hostile country across the world and infecting a random scientist with the plague?
This disease is generally highly treatable. Your conspiracy theory hinges on a belief that a treatable disease in a foreign country will be used to do something with the ongoing (ballots are already going out) US midterm elections, when in 2020 the US still held regular elections despite the ongoing, and far less treatable at the time, COVID pandemic.
Your hypothetical is not based in reality.