The successful development of genetically modified (GM) mosquitoes is a shot in the arm for medical science in its fight against malaria, which kills over a million children and infects an estimated 300 million every year. In places like sub-Saharan Africa — home to more than 90 per cent of malaria cases — the infection is actually on the rise, as mosquitoes develop resistance to insecticides and the malaria parasite mutates into different, and deadlier, strains that are immune to anti-malarial drugs.
Researchers from the Johns Hopkins University in Maryland, who produced the mosquito’s GM avatar, apparently altered the insects to make a protein that blocked the malaria parasite from invading the mosquito after having a blood meal. The idea is to let loose such insects that are resistant to the malaria parasite into natural mosquito populations so that the latter would be outnumbered. Although researchers always knew this was a good way to control malaria, the catch was that GM mosquitoes must produce more offspring in order to successfully replace their natural counterparts. This was a tall order until now. For any gene introduced into the mosquito usually disappeared within a dozen-odd generations, as crossing the descendants of a single, transformed individual led to inbreeding, exposing the new gene to deleterious mutations. Now that scientists seem to have found that the GM mosquito can indeed out-compete its natural cousins, it may not be long before suitable drugs and vaccines are developed to stop the parasite piggybacking on mosquitoes altogether.
There is quite some way to go before clinical trials involving humans bear out this optimism. It’s one thing for molecular biologists in sophisticated western labs to do exciting, if expensive, science, and quite another for the results to be made available to the world at large. So it is up to developed countries — where such cutting-edge research is carried out — to show the political will to translate this high-tech genome research into low-tech control strategies for developing countries. Only then will it be possible to eradicate malaria from the world.