Here's an overall strategy guide!
First off, When you start out, get your infectivity up to about 3 or 4 keep your drug resistance and lethality at 1. Then, for the next few rounds, spend all your points on spreading your virus until EVERYONE in the country is infected (ALL the little people turn red). Then, keep spending points on the airport until the icon turns red. The next round a new country will be infected. With this new country again spend every point on spreading your virus until everyone is infected. After that, put your points into the airplane again until the icon is red. Do this with all the countries until everyone in every country is infected. After EVERYONE IN THE WORLD is infected with your virus, lower infectivity back to 1. Then spend all your points on drug resistance until it is about 3 or 4. For the next few rounds, spend every point on destroying all traces of cure. Go for the countries with the highest cure percentage done first (usually countries with one-fifth done can be put aside for now and you can focus on the ones with two-fifths and even three-fifths). Then after ALL THE CURE IS GONE IN THE WORLD, put drug resistance back to 1 and spend all your points on lethality until it is 4 or even 5 and let the fireworks fly. For the next few rounds, spend your points on poisoning the water supplies until the little water icon turns red (starting with the most populated countries). Then, hit the end turn button a few times and your done! Congratz!
Tips:
When infecting the planes, use the countries with the most population still alive, dead people don't fly on the planes.
Don't even try to poison Greenland's water supply, I spend about 20 points on it with no result (damn mountian water).
Don't just click the button madly, check each countries status before you end the turn.
Never lower any skill below 1, you lose effectiveness without gaining any points.
You spend more points to upgrade your virus than you get back for downgrading it. (For instance If I went from 1 to 2 it might cost me 4 points, but if I downgrade it back to 1 I might only get 3 points back.)
Pretend that you're Agent Smith.
Have Fun, hope this helped!
