Onb3k3nde works ok but you nedd something to make it letahal so here's mne.
1 Pick Virus
2 Start in Canada, Greenland, New Zealand, Cuba, or madagascar (if not, restart)
3 Sell starting symptoms (if any), other than sneezing. If you don’t have sneezing, buy it but make sure your virus has LETHALITY or it will not work.
4 Buy 1-1-1-0 Resistances
5 Once your disease spreads to a few countries, sell sneezing to get rid of visibility
6 Wait until all countries are infected. If Madagascar closes or this is after day 30, restart
7 Pump 4 Drug Resistance and buy sneezing, coughing, vomiting
8 After a few days, unlock tier 2-3 keeping whatever symptoms it gives you
9 Buy fever, fatigue, diarrhea, pulmonary edema, hypersensitivity, hemorrhaging
10 Wait until everyone dies