Aug. 12, 2025 | Austin, Minn. — Powassan virus (POWV), a type of flavivirus closely related to the Zika and Dengue viruses, is an emerging tick-borne virus spreading across North America. In humans, it can cause symptoms like brain swelling, paralysis, seizures, and coma. Its mortality rate is estimated to range from about 12.5% to 17.9%, and survivors often experience long-term neurological symptoms. To date, there are no vaccines or antiviral treatments for POWV.
New research published by Professor and CryoEM Director Susan Hafenstein, PhD, and Graduate Assistant Sayan Das at The Hormel Institute, University of Minnesota, in the leading scientific journal Science Advances could take us closer to developing therapeutics.
“Essentially, we made a lookalike version of the Powassan virus: one that walks like Powassan, talks like Powassan, but will not cause disease and is safe to handle in the labs. Think of it like building a movie prop of a dangerous animal where you get the full appearance of the animal and their behavior, but without the bite,” Das said. “The beauty of this approach lies in the fact that although it looks like wild-type Powassan virus, it is absolutely safe to study in a BSL-2 setting.”
Using cryogenic-sample electron microscopy (cryoEM) technology, one of the world’s most powerful forms of microscopy, The Hormel Institute scientists generated an atomic-level, high-resolution 3D structure of POWV. That allowed them to observe sugar molecules on the virus’s shell that play a role in how the virus attaches to enter the human host. They also discovered three secret lipid pockets within the virus that are crucial to its stability—and “one of which might just prove to be the virus’s Achilles heel,” Das explained.
“The project is a beautiful intersection of curiosity, collaboration, and public health,” Das said. “Our study not only provides a structure of the virus, but also helps establish a suitable platform to study this virus safely, design safe and effective vaccines against it, and develop antivirals to treat infections. To me, this project is a perfect example of how science can be used to solve real-world problems.”
This project was done in collaboration with the Department of Biochemistry and Molecular Biology and The Huck Institutes of the Life Sciences at The Pennsylvania State University, as well as the U.S. Department of Agriculture.
You can read the paper here: https://doi.org/10.1126/sciadv.adw7700
Research highlights:
- This study provides the first atomic-level structure of Powassan virus (POWV), which is spreading across North America via ticks and can cause fatal brain infections in humans.
- Researchers were able to create a chimeric Powassan virus platform in order to study the virus in a safe manner. This approach reduces risks and barriers, making it possible for researchers to test vaccines, and design antivirals against it without the requirement of high-containment facilities.
- Researchers discovered lipid pockets sequestered within the virus that could be used for designing lipid-based antivirals against flaviviruses like POWV.
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Founded in 1942 by Jay C. Hormel and The Hormel Foundation, The Hormel Institute, University of Minnesota, makes scientific advancements that enhance wellbeing and extend human life. For more than 80 years, we have pursued our mission to conduct research and provide education in the biological sciences with applications in medicine and agriculture. A part of the University of Minnesota's Research and Innovation Office, The Hormel Institute partners with the region's leading biomedical research facilities, including Mayo Clinic.