Lets say I am Nigerian male. I take the the vxgn vac. Now rather than having a 100% chance of my pecker falling off, I only have a 70% chance now. Thats a hell of a deal. What do you plan on selling this wonder drug for? Better give it away. Sounds alot like Enron trying to sell power to India. Helps not to do business with deadbeats.
If a Nigerian village woman is the wife of a truck driver who has frequent sex with a prostitute who has sex with men infected with AIDS, and all 3 receive from an international organization a vaccine with a 40% efficacy, the chance of the village woman contracting HIV becomes .6 X .6 X .6 = .216 --- instead of a 100% chance of getting AIDS, the village woman now has only a 21.6% chance of getting AIDS. --- actually less than that, because sometimes you can get lucky and have unsafe sex yet not catch the HIV virus.