Health

The Ethical Risks of Engineering Mosquitoes Into Extinction To Stop Zika

CREDIT: AP Photo, Silvia Izquierdo

Army soldiers set up a sign that reads in Portuguese "A mosquito is not stronger than an entire country" at the Central station in Rio de Janeiro, Brazil, Saturday, Feb. 13, 2016.

Since news of the Zika virus first hit mainstream media, government officials, global health leaders, and the panicked general public have been clamoring for solutions to stop the rapidly-spreading disease. As thousands of women in an increasing number of countries give birth to babies with severe brain defects linked to the virus, scientists are racing to come up with answers.

One of the leading solutions floated sounds like it came straight from the pages of a science fiction novel: Getting rid of mosquitoes, the “flying syringes” responsible for Zika’s rapid proliferation, altogether.

Mosquitoes kill an average of 725,000 people every year. At nearly twice the number of people murdered by humans each year, this makes mosquitoes the deadliest species on earth. It also makes them a constant focus of scientific research. Since the late 1800s, when scientists first made the connection between malaria and mosquito bites, the seemingly insignificant insect has been a topic of important research — and the messenger of at least a dozen fatal diseases.

It may seem logical, then, to simply kill mosquitoes, and with them, the diseases responsible for killing tens of thousands of people every year. But is it a good idea?

Experts in the field are concerned that attempts to effectively wipe an entire species from the planet could end up having a devastating effect on the global ecosystem. But with thousands of babies being born with shrunken brains, primarily to impoverished women living in countries where abortion is criminalized, scientists are questioning their responsibility to expedite a process likened to “playing God.”

At a Tuesday event in Washington, D.C., a day after President Obama requested $1.9 billion in funds to combat the virus, a panel of epidemiologists, global policy experts, sociologists, and geneticists questioned the ethics of letting scientists take the evolutionary reins.

“It is not something that we should do lightly — to deliberately alter the traits of a wild population,” said Kevin Esvelt, a genetic researcher at MIT’s Media Lab. “Even with something like a mosquito, which most of us are probably not very fond of, there might be unexpected ecological side affects.”

The discussion focused specifically on the newest, most promising solution for eradicating mosquitoes: Gene drives.

Named for their ability to “drive” genes through populations over many generations, this technology throws a wrench into what you learned in high school biology class. Instead of a species’ offspring having a 50 percent chance of inheriting a parent’s gene, gene drives rig the game to ensure that a gene will be inherited by all offspring. New technology has made it possible for scientists to manually trigger gene drives in a species — and, in some cases, choose exactly which trait to modify and how. As in the regular natural selection process, this would have to pass through many generations to see change. But the life expectancy of the mosquito responsible for transferring most diseases is — at most — a month.

A gene drive could erase the trait allowing mosquitoes to reproduce, eventually spreading throughout the population. Or scientists could find a way remove the gene holding Zika bacteria from the mosquito gene pool, an approach recently used to create malaria-resistant mosquitoes.

Though this process may seem like a silver bullet to end the Zika virus, there’s universal agreement that it’s wildly dangerous.

“We now have the power to hijack evolution,” said Eleonore Pauwels, a member of the Science and Technology Innovation Program at the Woodrow Wilson International Center for Scholars in Washington, D.C. “Many people think it’ll be efficient and predictable. But that’s not the case here. We need to know how to talk about to the public, so they understand the risks.”

If the tools fell into the wrong hands, someone could easily drop irreversible damage into the human gene pool — a risk worthy of the technology being deemed a weapon of mass destruction by the U.S. Director of National Intelligence earlier this month.

Pauwels said the lack of knowledge the general population has about the gene drive process — and its risks — is its own “national security problem.” She cited an argument that’s been brought up during past epidemics: Leaving these monumental choices, ones that could alter humanity, up to a small group of elite scientists is unethical on a equity level. Most panelists agreed, but offered little answers to the problem.

“Most people don’t have the bandwidth to think critically about these issues, they’ve got other things to worry about — like getting to work on time, feeding the kids, making enough money to live,” said Andrew Maynard, a professor at Arizona State University’s School for the Future of Innovation in Society. “So then the question is: How do we make decisions in an area like this [as a civilization] where we actually don’t have the mechanisms to engage with large sectors of the population?”

Most of the women affected by Zika live in remote areas of developing countries, and are limited by the amount of information filtered through government channels. Likely, the last thing on their mind is researching a technological solution that could take years of debate before it’s released to the public. Panelists concluded that short-term solutions, like expanding women’s access to reproductive services (like contraceptives and abortions), may have to hold over Zika-affected countries until an ethical process is agreed on.

Not all scientists agree. Brazil has already welcomed British biotech firm Oxitec, the private company leading the development of genetically-edited mosquitoes, into the country. Instead of a gene drive, Oxitec genetically engineers mosquitoes to produce larvae that dies after about four days. Still, many are skeptic of their decision to release these mutant mosquitoes into the wild, and their release has ignited an online conspiracy theory blaming Zika’s existence on the genetically modified mosquito.

These theories are exactly what the panel’s scientists want to avoid. Clarity and understanding should precede fear. In the words of MIT’s Esvelt: “If Zika is what it takes to talk seriously about gene drives in advance of experiments, so that the public conversation can demand that those experiments are transparent, that’s a silver lining to Zika. And we’d be fools not to grasp it.”