It’s been a while since we’ve talked about it here, but the Zika virus hasn’t gone away; the problem of how to address it—develop a vaccine? Try to stop its path of transmission?—is still very much with us.
One way to slow it down, at least, is to eradicate the mosquitoes that spread the virus. Brazil and other countries have been making mighty efforts in that direction, involving, among other things, spraying insecticides and eliminating pools of standing water. Officials in many countries have launched education programs to make people aware of the hazards of empty flowerpots, abandoned tires, and other seemingly harmless objects that can hold rainwater and offer a potential breeding ground to mosquitoes.
About two years ago, Brazil also began experimenting with the release of genetically modified Aedes aegypti mosquitoes. The British company Oxitec set up a facility in Piracicaba where it released modified male mosquitoes that mated with females and produced offspring that died before they were able to fly. The company reported a reduction of 80% or more in mosquito populations in areas where the modified males were released. The US Food and Drug Administration approved a similar trial in Florida, which had some of the earliest cases of Zika in this country, but it was delayed because of residents’ objections.
How concerned should we be about the use of genetically altered mosquitoes? This editorial by Henry T. Greely, a Stanford law professor who specializes in the implications of new biomedical technologies, argues that we should worry about genetic modification not necessarily for the reasons many people do—such as modifying the human genome in unacceptable ways or creating “designer babies”—but rather because the technology may become so widespread that almost anyone can have access to it. For example, the gene-editing tool known as CRISPR is readily available; you can buy a do-it-yourself CRISPR kit for less than $200. In fact, notes Greely, “CRISPR is simple and ubiquitous enough that a biology major with a thousand dollars and a kitchen could start changing microbes, plants, and some animals.”
He points out, “The problem of regulating CRISPR is similar to what the Federal Aviation Administration faces with drones. It is used to dealing with airlines and even private pilots, but hundreds of thousands of recreational drone owners cause real difficulties.”
He continues, though, “Even if all the actors can be regulated, how should they be regulated? What level of pre-approval or oversight is necessary for what kinds of work, and what level would stifle valuable innovation? Who will decide what is safe, and how safe is safe enough?”
He cites work by the Gates Foundation to release modified mosquitoes in Africa—in this case, to try to reduce cases of malaria, not Zika—as an example of beneficial gene editing, but he also notes, “Someone, somewhere, is probably trying to use genome editing to try to turn a harmless microbe into a biological weapon—changing, say, mousepox into smallpox.”
What do you think? Is modifying mosquitoes a reasonable approach to take against Zika? Should we concentrate on other means instead, such as eliminating their habitat—which in turn will put more emphasis on the maintenance of stormwater detention and conveyance systems?