White-nose syndrome vaccine update and research on host protection mechanisms Active
Sixteen years after Pd, the fungus that causes white-nose syndrome in bats, was first recognized in New York, its range now extends to the Rocky Mountains, and it has been definitively detected in all but seven states (Alaska, Arizona, Florida, Hawaii, Nevada, Oregon, and Utah). The National Wildlife Health Center and our partners continue to field test a WNS vaccine for wild bats and to research host mechanisms of protection against Pd.
Why this matters: White-nose syndrome continues to spread in North America and has substantially impacted bat populations, including declines of over 90% in northern long-eared, little brown and tri-colored bat populations in less than 10 years. We are developing tools and management strategies to protect bat populations from white-nose syndrome and to help preserve these important species and the ecosystems they live in.
White-nose syndrome vaccine research update
To assess the efficacy of vaccination to prevent white-nose syndrome (WNS), researchers from the USGS National Wildlife Health Center (NWHC) and the Wisconsin Department of Natural Resources conducted field studies in several populations of susceptible bats. In two large Wisconsin hibernacula where a subset of little brown bats (Myotis lucifigus) was treated for three years (fall of 2019-2022), vaccinated bats had significantly lowered winter Pseudogymnoascus destructans (Pd) pathogen loads compared to bats that received a placebo. Higher rates of and later emergence were noted among
vaccinated bats compared to non-vaccinated bats in the spring of 2020, but not since then. Bats in the Wisconsin hibernacula have been exposed to Pd since about 2013 and their numbers declined quickly, but evidence is accumulating the last few years that suggests bats at these sites may be developing resistance to the disease. Their population numbers are increasing, while their Pd loads in general are decreasing. Vaccination against WNS is likely to be more effective prior to or immediately after disease emergence. To test this hypothesis, NWHC and partners from the Texas Parks and Wildlife Department, Washington Department of Fish and Wildlife, and Idaho Fish and Game have begun vaccine efficacy studies in those states in locations where Pd was recently discovered, treating bats in both hibernacula and maternity colonies. Additional sites are being considered in Colorado, Wyoming, and Nevada. In addition to little brown bats, several other Myotis spp., including cave myotis (M. velifer), Yuma myotis (M. yumanensis), long-eared myotis (M. evotis), and long-legged myotis (M. Volans) have been vaccinated. Results of these efforts will be forthcoming.
Assessing host mechanisms of protection from white-nose syndrome
White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans (Pd), has decimated many North American bat populations. Despite its devastating effects, recent studies have demonstrated that some susceptible bat populations are persisting with, and even recovering from Pd infections (Cheng et al. 2019, Frank et al. 2019, Frick et al. 2017, Langwig et al. 2017, Lilley et al. 2016). Researchers at NWHC, Virginia Tech University, Bucknell University, Montana Fish, Wildlife and Parks, Montana Natural Heritage Program, New York State Department of Environmental Conservation, and Wisconsin Department of Natural Resources recently collaborated on a project to assess host protection in little brown bats (Myotis lucifugus) under controlled environmental conditions at NWHC. Bats collected from a historical gradient of WNS exposure, ranging from the eastern U.S. (persistent) to the mountain west (naïve), were placed into hibernation chambers stratified by source population, held at a constant temperature and humidity, and challenged with Pd to determine if locale-based time since disease emergence has produced physiological changes which alter individuals’ ability to tolerate or resist infection. A subset of field vaccinated bats from the Midwest (Wisconsin) were included. The study, completed in the spring of 2022, found that survival among eastern and both vaccinated and unvaccinated midwestern populations was similar and relatively high, while the western population had lower survival rates. To assess potential mechanisms that may affect susceptibility, next steps include analyzing quantitative pathogen loads relative to survival, change in mass, white blood cell differentials, chemical panels, RNA expression in wing tissue, immune markers in plasma, torpor bouts and lengths, and tissue histology. RNA sequencing of wing tissue samples was recently completed, and all other analyses are currently underway.
Field trials for testing of white-nose syndrome vaccine candidates
Vaccines
White-Nose Syndrome Surveillance
White-Nose Syndrome
Sixteen years after Pd, the fungus that causes white-nose syndrome in bats, was first recognized in New York, its range now extends to the Rocky Mountains, and it has been definitively detected in all but seven states (Alaska, Arizona, Florida, Hawaii, Nevada, Oregon, and Utah). The National Wildlife Health Center and our partners continue to field test a WNS vaccine for wild bats and to research host mechanisms of protection against Pd.
Why this matters: White-nose syndrome continues to spread in North America and has substantially impacted bat populations, including declines of over 90% in northern long-eared, little brown and tri-colored bat populations in less than 10 years. We are developing tools and management strategies to protect bat populations from white-nose syndrome and to help preserve these important species and the ecosystems they live in.
White-nose syndrome vaccine research update
To assess the efficacy of vaccination to prevent white-nose syndrome (WNS), researchers from the USGS National Wildlife Health Center (NWHC) and the Wisconsin Department of Natural Resources conducted field studies in several populations of susceptible bats. In two large Wisconsin hibernacula where a subset of little brown bats (Myotis lucifigus) was treated for three years (fall of 2019-2022), vaccinated bats had significantly lowered winter Pseudogymnoascus destructans (Pd) pathogen loads compared to bats that received a placebo. Higher rates of and later emergence were noted among
vaccinated bats compared to non-vaccinated bats in the spring of 2020, but not since then. Bats in the Wisconsin hibernacula have been exposed to Pd since about 2013 and their numbers declined quickly, but evidence is accumulating the last few years that suggests bats at these sites may be developing resistance to the disease. Their population numbers are increasing, while their Pd loads in general are decreasing. Vaccination against WNS is likely to be more effective prior to or immediately after disease emergence. To test this hypothesis, NWHC and partners from the Texas Parks and Wildlife Department, Washington Department of Fish and Wildlife, and Idaho Fish and Game have begun vaccine efficacy studies in those states in locations where Pd was recently discovered, treating bats in both hibernacula and maternity colonies. Additional sites are being considered in Colorado, Wyoming, and Nevada. In addition to little brown bats, several other Myotis spp., including cave myotis (M. velifer), Yuma myotis (M. yumanensis), long-eared myotis (M. evotis), and long-legged myotis (M. Volans) have been vaccinated. Results of these efforts will be forthcoming.
Assessing host mechanisms of protection from white-nose syndrome
White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans (Pd), has decimated many North American bat populations. Despite its devastating effects, recent studies have demonstrated that some susceptible bat populations are persisting with, and even recovering from Pd infections (Cheng et al. 2019, Frank et al. 2019, Frick et al. 2017, Langwig et al. 2017, Lilley et al. 2016). Researchers at NWHC, Virginia Tech University, Bucknell University, Montana Fish, Wildlife and Parks, Montana Natural Heritage Program, New York State Department of Environmental Conservation, and Wisconsin Department of Natural Resources recently collaborated on a project to assess host protection in little brown bats (Myotis lucifugus) under controlled environmental conditions at NWHC. Bats collected from a historical gradient of WNS exposure, ranging from the eastern U.S. (persistent) to the mountain west (naïve), were placed into hibernation chambers stratified by source population, held at a constant temperature and humidity, and challenged with Pd to determine if locale-based time since disease emergence has produced physiological changes which alter individuals’ ability to tolerate or resist infection. A subset of field vaccinated bats from the Midwest (Wisconsin) were included. The study, completed in the spring of 2022, found that survival among eastern and both vaccinated and unvaccinated midwestern populations was similar and relatively high, while the western population had lower survival rates. To assess potential mechanisms that may affect susceptibility, next steps include analyzing quantitative pathogen loads relative to survival, change in mass, white blood cell differentials, chemical panels, RNA expression in wing tissue, immune markers in plasma, torpor bouts and lengths, and tissue histology. RNA sequencing of wing tissue samples was recently completed, and all other analyses are currently underway.