Anti-lyme disease vaccine for mice could help prevent human infections
HARTFORD – Connecticut researchers are involved in a new and potentially important effort to break the cycle of infections among wild animals and ticks that leads to the transmission of Lyme disease to humans.
The key is finding a way to give a specially developed vaccine to white-footed or deer mice, carriers that are one of the major ways that Lyme disease bacteria get into the ticks that eventually infect humans.
Scientists at the Connecticut Agricultural Experiment Station recently finished a three-year study that provided vaccine-coated food pellets to mice in the backyards of 32 homes in Redding.
In a recently published paper on the study, researchers reported a 26% drop in the number of Lyme disease-infected white-footed mice trapped at those Redding homes. Fewer infected mice means fewer infections in the ticks that bite them and then later go on to bite humans.
The intent of the Redding field trial was to “target the rodent reservoir (of Lyme disease bacteria) to reduce tick infections,” said Scott
Williams, an agricultural scientist at the experiment station and one of the coauthors of the paper.
“Fewer infected ticks mean less infection in the field overall,” said Kirby
Stafford III, the state entomologist and chief scientist at the Connecticut Agricultural Experiment Station.
Stafford also said that repeated applications of the vaccine to generations of wild mice would result in even greater long-term reductions in the incidence of ticks carrying Lyme disease bacteria. He said the “decrease would be greater year-over-year that the vaccine is applied.”
“I agree with that,” said Jolieke van Oosterwijk, chief scientist at US Biologic, the Memphis, Tenn.based research company that developed the vaccine pellets and paid for the Connecticut field trial. “Every year (of application of the vaccine in an area) will have an added effect,” van Oosterwijk said.
She called the results from the Connecticut field trial “very encouraging numbers.”
US Biologic is now seeking regulatory approval to sell these anti-lyme disease mouse-food pellets to the general public, but company officials declined to speculate as to when those approvals might come.
“We’re rapidly moving through the process,” said US Biologic’s executive vice president, Chris Przybyszewski, who was also a co-author of the published scientific paper on the Redding study. “We’re really looking forward to marketing this and making it available to folks.”
But there remain numerous questions about this approach to the fight against Lyme disease, which the U.S. Centers for Disease Control and Prevention lists as the most common illness transmitted by ticks, mosquitoes or fleas in the United States.