With all the recent talk of a new Zika vaccine being tested, a CDC travel warning to Miami and anxiety about Zika infecting Olympic athletes in Rio, it has been forgotten that there is already a technology that can target the species that is spreading Zika throughout the Americas and cause it to wipe itself out. That tech is potentially powerful, but it also carries potentially extreme implications.
Now British startup Oxitec is on the verge of getting a rare (if not unprecedented) emergency license to use this tactic. Following trials in the Cayman Islands, in Panama and in Piracicaba, Brazil, they are waiting to start a trial in the Florida Keys.
“We have developed an Aedes aegypti mosquito with a ‘self-limiting’ gene, which causes its offspring to die,” Matthew Warren of Oxitec told Geektime by email. “We release male mosquitoes (males don’t bite or transmit disease), and they go and search for wild females to mate with. They pass the self-limiting gene on to their offspring, which die before reaching adulthood. With repeated releases this results in a reduction in the wild population.”
Dr. Andrew McKemey, who led the Brazil trial, let journalists know that things were on the fast track right now to get things deployed in Florida, saying, “We expect a decision any minute now. We’ve already built a laboratory there — a mass production unit — so we could start immediately.”
And by mass production, Oxitec means it is producing 60 million genetically modified mosquitoes a week.
The biggest threat Zika poses is microcephaly, an abnormality that causes babies to be born with disproportionately small heads. The aedes aegypti variety of mosquito responsible for spreading it is also responsible for spreading Dengue and Yellow Fever. Oxitec’s field tests have yielded massive results according to the company.
“In all of these, releases of our mosquitoes reduced the wild Aedes aegypti population by more than 90% (in comparison, current methods like insecticides can only reduce the population by 30-50% at best),” Warren illustrated to Geektime. As an invasive species from outside the Americas, the case is strong to target the breed for extinction without concern for harmful effects on the classic ecology of infected areas.
“The Zika threat is here and now and there is now local transmission in Florida so that is why I urged Congress to seriously consider emergency use,” Oxitec CEO Hadyn Parry told the Telegraph, discussing his recent visit to Capitol Hill in Washington D.C. as a prelude to the fast-track permission to deploy in southern Florida. The state is currently spraying a 10-square-mile-wide area where infections are concentrated.
There is newer approach also being discussed that shows some promise as well. A genetic technology exists that has the power to wipe out the mosquito that carries Zika, or any other specific variety of mosquito. Called “gene drive,” the technique uses the CRISPR method of gene snipping to modify an animal’s genetics. The genetic change is spread to the next generation (in this case, mosquito to mosquito). Over time, gene drive can reinforce inherited traits that actually make the animal weaker, undermining the ability of species to thrive, eventually wiping it out.
“We could have it easily within a year,” UC Irvine molecular biologist Anthony James told MIT Technology Review back in February. But this is a much longer term approach without the legacy that Oxitec’s technology has.
“Gene-drive systems are different from our approach [in that] they are designed to establish themselves permanently in the environment, and cannot be recalled once released,” Warren emphasized. “This raises concerns about potential irreversible changes to vector and disease dynamics . . . the gene-drive method has so far only been restricted to the lab.”
For now, Oxitec seems to have the lead in the fight against Zika, showing much more immediate results. Founded in 2002, the Oxford spinout has 65 employees. Could this be the counteroffensive that devastates the Zika virus? Only time will tell.