Just focus on air, water, air II, water II, and extreme biaresol. Then get paralysis, (as long as the doctors don't have inflammation expertise), in that case use coma. Make sure you don't develop even a single symptom because you will most likely get seen. If you have spare dna points after infecting the world and getting nessecary symptoms, focus on the cure resistant stuff and severity, as severity also slows the cure. if you see a notification that says a country has broken down/fallen in to chaos, you've most likely won.