Brazilian health authorities have taken the lead in the fight against dengue fever not with vaccines but rather with mosquitoes. At the start of this week they expanded their program and opened a large-scale mosquito farm in the northeast state of Bahia.
Now, these are not the garden-variety mosquitoes, they are an army of genetically modified male mosquitoes being used to combat, rather than spread, disease. In the laboratory, male mosquitoes are genetically modified to carry a lethal gene against the dengue virus. They are then released into the wild to mate with female mosquitoes (who are actually the ones who bite humans – since they need the blood for their eggs) and once the lethal gene is passed on to the offspring they die in the larvae stage and never make it to adulthood.
The target is dengue fever, for which there currently is no vaccine, and prevention largely has failed.