I infected madagascar. What I did was- I immediately removed all symptoms, then just left it running for about an hour or so. That way, I accumulated ~100 DNA points, but only infected 20-30 people. Then, I quickly purchased everything that would propagate the disease faster (some of the low-level symptoms, + all resistances). Madagascar got infected (by chance, I guess), and somehow my bacteria became immune to vaccine. Then I just bought the killing symptoms, and wiped out the population of earth.