The black-legged tick can carry the bacterium that causes Lyme disease.
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By Jennifer Couzin-Frankel
Months after a U.S. Congress–mandated working group sounded the alarm about tickborne illnesses and urged more federal action and money, the National Institutes of Health (NIH) is readying a strategic plan for these diseases. Last week it also, serendipitously, issued a rare solicitation for prevention proposals in tickborne diseases. The new pot of money, $6 million in 2020, represents a significant boost; NIH spent $23 million last year on Lyme disease, by far the most common tickborne illness, within $56 million devoted to tickborne diseases overall.
“I’m happy for anything” new going toward research, says John Aucott, director of the Johns Hopkins Lyme Disease Clinical Research Center in Baltimore, Maryland, who chaired the group that wrote the 2018 report. Strategies that may garner support include vaccines that target multiple pathogens carried by ticks or that kill the ticks themselves.
Aucott’s panel included academic and government scientists as well as patient advocates; it formed as a result of the 2016 21st Century Cures Act. The group’s report described tickborne diseases as a “serious and growing threat.” About 30,000 confirmed Lyme disease cases were reported last year to the Centers for Disease Control and Prevention (CDC), but the agency believes the real number to be more than 300,000. Cases of Lyme disease have roughly tripled since the 1990s as ticks carrying Borrelia burgdorferi, the causative bacterium, have spread in response to climate change, neighborhoods encroaching on animal habitats, and other ecologic shifts.
The Lyme disease field has for years been mired in controversy—researchers receive hate mail from angry and desperate patients, and scientific disputes can be vitriolic. That may have left government agencies reluctant to wade too deep into the fray. “I think the discussion is starting to shift,” says Monica Embers, a microbiologist at Tulane University in New Orleans, Louisiana. She and others still hope for additional money from NIH and CDC for diagnostics and treatment research. CDC’s budget for Lyme disease grew this year from $10.7 million to $12 million—the first increase in 5 years, albeit a modest one. “Preventing infection is going to go a long way if we can do it,” Embers says.
Symptoms of Lyme disease vary but can include a rash at the site of the tick bite, fever, fatigue, and swollen lymph nodes. After a course of antibiotics, 10% to 20% of those infected remain sick, and the question is why: Some scientists believe the bacterium can persist in the body, but others dismiss the idea. This dispute, combined with patients whom doctors often can’t help, has created a fractious field unlike almost any other.
The $6 million from the National Institute of Allergy and Infectious Diseases (NIAID), is slated to fund up to 15 projects. The funding “will get new technology out of the shadows,” spurring development of nascent approaches and collaborations, says Maria Gomes-Solecki, a veterinarian at the University of Tennessee Health Science Center in Memphis who has designed an oral vaccine for mice and other rodents against B. burgdorferi. It kills the bacterium in ticks feeding on the animals. A company called US Biologic, also in Memphis, is seeking marketing approval for the vaccine from the Department of Agriculture and hopes to sell it to homeowners and health departments.
“Vaccines are certainly going to be at the top” of prevention priorities for tickborne diseases, says Samuel Perdue, chief of the Basic Sciences Section in NIAID’s Bacteriology and Mycology Branch in Bethesda, Maryland, noting that the institute already funds some vaccine research.
The only Lyme vaccine for people had a difficult history: It was almost 80% effective but was pulled from the market in 2002 after safety concerns surfaced and sales tanked. Since then, tickborne diseases have become a growing problem, and the black-legged tick can transmit many of them, says Richard Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, New York. He favors developing a vaccine that protects against multiple pathogens, possibly by targeting ticks instead. Some scientists are studying how to design a tick-killing vaccine for people that reacts to the tick’s salivary proteins. Ostfeld knows firsthand that this is possible: After exposure to dozens of tick bites during fieldwork, his immune system now kills ticks when they begin to feed on him. “I’m not alone,” he says. “There are people who seem to attack the tick.” Animal models have backed the approach.
Nonvaccine prevention efforts are underway as well. Across 24 neighborhoods in Dutchess County in New York, Ostfeld and ecologist Felicia Keesing of Bard College in Annandale-on-Hudson, New York, are leading an effort to test whether a tick-killing fungus and a pesticide that kills ticks when applied to animals can reduce infection rates in people and pets. Much of that project is supported by the Steven & Alexandra Cohen Foundation, which has spent more than $42 million on Lyme and other tickborne disease research since 2015. Two other groups, the Global Lyme Alliance and the Bay Area Lyme Foundation, have together directed more than $20 million to research in recent years. “These foundations are giving a lot of money,” says Embers, who receives foundation support. “They want translational research, and they want answers.”
Foundations are keen to address the third rail of Lyme disease: how Borrelia bacteria persist—if they do—in treated patients who don’t get better. NIH’s strategic plan is due this summer, but Ostfeld says researchers coming together could make it easier for the agency to boost funding in a polarized field. “The responsibility,” he suggests, “lies at least in part with the community to try to avoid so much acrimony and to try to find areas of agreement.”
Source: Science Mag