I have only tested this on Normal, but I will assume it also works on Casual. May not work on higher difficulties.

This may sound like a joke, but the simplest way to win is to let people die. Find the virus, and let it spread. Make sure to get Authority 1-3, Declare Armageddon, and Expectation Management. Once the disease starts infecting and/or killing many people, get censorship. Once the censorship is thwarted, get fake news and wait to win. This may take a few attempts. Using this strategy you can beat the bio weapon in under a minute.

Probably everyone has already realized this but I thought this guide might help at least one person somewhere out there.

You'll probably also get the "Doomsday Save" achievement.