Scientists at MIT are hoping to prevent Lyme disease on the Vineyard by releasing large numbers of genetically engineered mice into the wild.
The project would still be years down the road.
The proposal comes as Island biologists and health experts are pressing for expanded deer hunts as a way to interrupt the life cycle of ticks, which carry a number of diseases and depend on deer for food and habitat. Funding for the Island’s tick-borne illness reduction initiative is expected to end this year.
Targeting white-footed mice could disrupt the disease transmission cycle itself, since ticks contract the pathogens from mice and other small mammals (and vice versa).
A large crowd gathered at the Edgartown Public Library last week to hear the proposal, led by Kevin Esvelt, an assistant professor of biology at MIT. He explained how genes from mice vaccinated against tick-borne diseases can be encoded into the reproductive cells of other mice. When those mice breed, their offspring are also immune.
His theory is that hundreds of thousands of engineered mice would be released on the Vineyard and Nantucket over time, and their genes would eventually spread to the population at large. An equivalent number could possibly be removed through trapping to balance the population size.
Mr. Esvelt said the project demonstrates a new approach to science that relies on transparency and community support. The public meeting last week was a first step in that direction for the Vineyard. “It is all too possible for individual scientists to build things in the laboratory that could affect potentially everyone,” Mr. Esvelt said. “We need to ensure that scientific research is done in the open.”
The Nantucket board of health last month indicated a desire to move forward with the project.
Mr. Esvelt helped pioneer a technique known as gene drive that could allow for the modification of entire species. He said the methods for targeting white-footed mice should be developed by a nonprofit to reduce public suspicion, with testing conducted separately.
Ultimately the process would involve a trial on a smaller island (there are several candidates) and would require a public vote to move forward, along with state and federal approval. The approach is meant to supplement other more conventional methods such as public education, yard maintenance and possibly deer culling.
The meeting included a panel discussion with Tufts University professor and tick expert Sam Telford, along with Dr. Michael Jacobs, an internist who co-founded the Vineyard Center for Clinical Research in 2014, and Mr. Esvelt.
Those who attended generally supported the proposal, but peppered the three panelists with questions related to ecological risks and the feasibility of other approaches.
Mr. Esvelt said he did not believe that engineering disease-resistant mice would lead to a “superbug” version of Lyme disease that is resistant to the mouse antibodies. And although he noted that “life finds a way,” he believed it was a question of how soon. “I will go out on a limb and say that it’s very, very, very unlikely,” he said of the superbug possibility.
Mr. Telford said he did not believe that removing Lyme disease (or ticks) would have any negative effects on the ecosystem.
“If God changed his mind . . . and took all the ticks away, we would never notice the difference,” he said. One species of wasp lays its larvae inside ticks, he added, but its presence on the Island most likely preceded the large tick populations. (It was also released here in the 1920s in an attempt to target dog ticks.)
The trial phase of the project may involve monitoring all the predators on the small island to be used as a test, including the tagging of owls, which feed on mice and other small animals. “We don’t know what might go wrong,” Mr. Esvelt said.
Targeting white-footed mice would not influence lone star ticks, which arrived on the Island more recently and depend on deer at every major stage in their life cycle. Lone star ticks have recently been found breeding in Aquinnah and Chilmark, and on Chappaquiddick, leading to a concerted push for deer culling on the Island.
Dr. Jacobs said he believes hunters would likely support a deer-reduction initiative on the Island. And Mr. Telford pointed to the invasion of lone star ticks on the Vineyard and problems the species has caused elsewhere in the region. “You will be miserable if you let it take hold here,” he said.
The conversation touched on the revolutionary gene drive technique, which ensures that nearly every offspring of an organism carries a given gene. “One organism could end up affecting everyone,” Mr. Esvelt said, again highlighting the importance of public oversight. “I think we are ethically required to do all of this research in the open.”
The program could target just the pathogen that causes Lyme disease, or it could immunize against tick bites in general, or it could do both. A show of hands at the meeting revealed a nearly unanimous support for the last option.
Leslie Serchuck, an infectious disease specialist, noted that there would likely still be opponents, and that their voices should be heard. “Anytime that anyone says anything — this can never happen, this won’t happen — has to be questioned,” she said. She also encouraged more public meetings and a deeper look at the risks.
Mr. Esvelt took a similar approach, inviting people to scrutinize the project. He agreed that human ingenuity has its limits.
“We are two-year-olds when it comes to understanding ecosystems,” he said. “We are six-year-olds when it comes to understanding biology at the molecular level. And right now the problem is that our power is vastly exceeding our understanding, which is why we need a new way to deal with this problem.”