Florida’s Feud Over Zika-Fighting GMO Mosquitoes

Categories: Health & Nutrition, Tech


It takes over two and half hours, emptying container after container, to release all the mosquitoes into West Bay. They’ve been doing this three times a week since July; residents used to grimace when they drove by, but now they barely glance over. The procedure seems more disruptive to those of us in the van. Each time Evangelou opens a container, a fair number of mosquitoes escape the wind tunnel and start buzzing around our heads. “There will be a few fliers, yeah,” Lacroix says with a smirk.

“A few” isn’t quite right. Before long, we’re overrun. Being in this van is like being in a Cheech and Chong movie, only with mosquitoes instead of smoke.

“Aren’t we going to get eaten alive?” I ask, trying not to sound too concerned.

“No,”Lacroix says. “They’re males.”

Male mosquitoes, he reminds me, aren’t the ones that bite. Just about the only thing male mosquitoes do, he says, is seek out females, which do the biting. Oxitec is trying to leverage this mating instinct to help wipe out one particular species of mosquito: Aedes aegypti, carrier and spreader of some of the worst insect-borne diseases known to medicine—dengue, malaria, and Zika. The A. aegypti mosquito has evolved to survive even the most effective pesticides. It can lay 500 eggs in just a bottle cap’s worth of water, and it prefers to bite humans over animals, so it lives in places where no one thinks to spray, like under the couch.

The idea behind Oxitec’s experiment is that if enough genetically modified male A. aegypti mosquitoes are released into the wild, they’ll track down large numbers of females in those hard-to-find places and mate with them. The eggs that result from any union with an Oxitec mosquito will carry a fatal genetic trait engineered into the father—a “kill switch,” geneticists call it. The next generation of A. aegypti mosquitoes will never survive past the larval stage, never fly, never bite, and never spread disease. No mosquitoes, no Zika.

Oxitec is far from the first company or research team that’s tried to sterilize an entire insect population. Scientists have been going after A. aegypti in this way since the 1970s, usually by irradiating them. The problem with radiation is that it makes the mosquitoes too weak to get out and breed. The great innovation of the Oxitec method is that it cleverly achieves the same result as sterilization, while leaving mosquitoes able to do what mosquitoes do.

The approach was developed by founder Luke Alphey, a British geneticist specializing in vector control, or the elimination of disease-bearing creatures. Oxitec has applied the method in Brazil, Malaysia, and Panama, often with partial support from the Bill & Melinda Gates Foundation, and claims to have reduced the A. aegypti population in tiny test areas by at least 90 percent. That’s a far better percentage than spraying, which usually hits about 50 percent and has a tendency to breed resistance, requiring more and more spraying to get the same low result.

“It takes one or two generations at least to be noticeable,” Lacroix says as he grabs a green fly swatter the size of a tennis racket and starts thwacking away at some of the mosquitoes flying around his head. A. aegypti’s life span ranges from two weeks to a month, so the company will know in a few months if the population is starting to decrease. If it is, Lacroix says, “we can roll out to the rest of the island, drawing down south through the peninsula.” Oxitec charges about $7.50 per person per year in each area it treats. While the price gets cheaper as the A. aegypti population decreases and fewer Oxitec mosquitoes need to be released, the treatments aren’t a short-term prospect: To ensure A. aegypti doesn’t come back, the company continues releasing its mosquitoes on an open-ended basis.

Chief Executive Officer Haydn Parry has called Oxitec’s method “a dead end” for the A. aegypti species. And, of course, in the age of Zika, such a dead end couldn’t be more desirable. Since the news emerged last spring that a spike in cases of microcephaly in Brazil appeared to have been caused by Zika, politicians and public-health officials from around the world have been beating a path to Oxitec’s door. U.S. officials were among them, even as Congress dithered all summer before finally, in late September, approving the funding of countermeasures to prevent large outbreaks. “I don’t think time is on our side,” Parry told a congressional committee in May. “I think the utmost urgency is required. I’ve just come fromPuerto Rico, and we could have a catastrophe on our hands if we are not careful.” The big winner ifOxitec ends up enlisted to fightZika in the U.S. would beIntrexon, abiotech company run by billionaire Randal Kirk, which acquiredOxitec for $160 million in the summer of 2015.

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