It should also be noted that bed nets can be rendered ineffective by such things as rolling over or throwing an arm out in your sleep. If the net is touching the skin, the mosquitoes can bite right through it. Proper use requires a good bed and a well-built house, so that you can suspend it around the bed. (And the bed can't be overloaded - if there are several people in the bed you're more likely to touch the sides of the net.)
Bed nets are common in the areas affected. But they are finicky, annoying, and intrude on your life. A bed net is fine and good - but so is sitting on the porch drinking a beer with your friends while you watch the sunset. (Which will put you at risk.) A vaccine which could effectively knock down a large portion of the risk, and possibly reduce the infected pool for the mosquitoes to draw from, would be much better in the long run.