A small group of scientists in California and Massachusetts are raring to use a new genetic technology touted to capably wipe out the Zika-carrying mosquito.
Dubbed gene drive, the controversial technique is still in experimental stages. It was demonstrated only in 2015 in fruit flies, yeast cells, and a malaria-transmitting mosquito species, and uses the gene-splicing technology CRISPR to force the spread of a genetic change through a population as it reproduces.
Now, gene drive is hoped to eliminate local Zika-spreading Aedes aegypti mosquito populations in Latin America and the Caribbean, and simultaneously deter the spread of dengue and other diseases that the same bug transmits.
“Quite a few people are trying to develop a gene drive for population suppression of Aedes,” said scientist and mosquito-controlling genetic technology expert Anthony James from the University of California, Irvine.
In 2015, his team used gene drive to produce mosquitoes equipped with an immune system that stunts the transmission of the malaria-causing parasite.
Unlike existing genetic technologies for mosquito control, gene drive could wipe out entire disease-transmitting mosquito population in a matter of months – as well as cheaply mobilizing fewer lab-created mosquitoes than similar approaches.
According to James, funding would allow them to get gene drive ready for that purpose in less than one year and have it undergo field trials.
Gene drive pioneer Kevin Esvelt of Massachusetts Institute of Technology said that Zika is already part of the hit list of global collaborations targeting Aedes populations.
Since the Aedes mosquito carries not only Zika but also other infections such as dengue and yellow fever, it would make sense to engineer a gene drive that turns insects sterile instead of simply making them unable to spread the virus. “You want to go for population suppression,” he said.
Releasing a gene drive out in the wild, however, would surely stir controversy and trigger debate. A report from National Academy of Sciences experts, for instance, will release this May their verdict on the responsible use of this gene technology.
“I don’t think there is a real consensus yet on gene drives,” said study Director Keegan Sawyer.
Environmental scientist Todd Kuiken harped on the interconnectedness among species including in the tropics – something that annihilating a certain species will definitely affect.
“My concern is more the ecological interactions,” Kuiken warned.
Esvelt, while remaining outspoken about the need to proceed with gene drive with caution, echoes the goal of Aedes eradication given proven safety and public consensus.
So far, no public health agency or health-funding foundation has expressed support for this specific mission to extinguish the rapidly spreading Zika virus.
Photo: Agencia Brasilia | Flickr