The HEART-RENDING images of Brazilian infants with microcephaly — linked to the rapidly spreading mosquito-borne Zika virus — have brought the crisis into sharp relief and prompted heated debate over the use of a newly discovered gene-editing technology to eliminate the invasive Zika-carrying mosquito. That technique, known as CRISPR, would allow biologists to edit the DNA of the Aedes aegypti mosquito, which also transmits dengue and chikungunya viruses. Using CRISPR, biologists could modify a specific gene in the targeted species — so that it created only male progeny, for example. Through a process known as gene drive, that modification would rapidly spread within the population, wiping it out in a matter of months. Getting rid of the mosquitoes entirely, the argument goes, will also eradicate the diseases they carry.
Scientists in California and here in the Bay State are already experimenting with gene drive — a faster process than developing a vaccine — in an effort to stop the outbreak dead in its tracks. But with that power comes responsibility: The possibility of saving lives must be balanced against concerns about unintended consequences.
“It’s very important to test [a gene drive] a lot in the lab before it’s released,” says Flaminia Catteruccia, a professor of immunology and infectious disease at the Harvard T.H. Chan School of Public Health. “It’s also critical to have a system in place to ‘withdraw’ the gene drive to reverse any unforeseen damage. A contingency plan has to be ready.”
Questions abound: What is the environmental impact of genetically altered mosquitoes? Is it ethical to erase an entire species? Federal funding and more collaboration between government agencies and laboratories currently trying to develop a gene drive are a vital part of the equation. “We need centralized actions and decisions that should not slow down research,” adds Catteruccia. “If we want to safely implement [a gene drive], there needs to be concerted action.”
Although the World Health Organization has declared Zika an emergency, the response should involve top scientific agencies, such as the National Institutes of Health in the United States, as well as humanitarian organizations. And government officials should keep the ethical debate moving at the same speed as the science.
