3D Mapping of Powassan Virus Structure Offers Hope for Future Treatments

In a groundbreaking study published on July 9, 2025, researchers at Penn State University, in collaboration with the University of Minnesota and the U.S. Department of Agriculture, unveiled a high-resolution, three-dimensional (3D) structure of the Powassan virus (POWV), a tick-borne virus that has seen rising infection rates across North America. This research, led by Dr. Joyce Jose, an associate professor of biochemistry and molecular biology at Penn State, aims to shed light on the virus's structure to pave the way for potential vaccines and treatments, as currently, no effective therapies exist for POWV infections.

The research highlights the urgent need for understanding POWV, which can lead to severe neurological complications including encephalitis and seizures. "We need to know the structure of this virus to develop strategies for treatment and prevention," explained Dr. Jose. The findings were published in the peer-reviewed journal *Science Advances* and have significant implications for public health, particularly as tick populations expand their geographic range due to climate change.

POWV is a member of the Flaviviridae family, which includes other notorious viruses such as West Nile and dengue. Ticks serve as the primary vectors for transmitting POWV, complicating research due to the challenges associated with studying live viruses. Traditionally, researchers have relied on chemical or ultraviolet inactivation methods, which can damage the virus's structure and hinder accurate analysis. To overcome this, the research team utilized a surrogate model by modifying the less infectious yellow fever vaccine virus, effectively replacing two of its protein genes with those from POWV to study its structural characteristics safely.

Utilizing advanced Cryo-Electron Microscopy (cryo-EM), the team achieved unprecedented clarity in visualizing the virus, allowing them to observe the arrangement of its surface proteins in a herringbone-like pattern. "This technology has transformed our ability to study viruses," stated Dr. Jose. "We can now see how every molecule sits on the virus surface, which is critical for understanding how it transmits disease."

The research team’s findings indicate that the host type for POWV is determined by nonstructural proteins rather than the structural proteins observed on the virus surface. This discovery suggests that understanding these interactions is vital for future research into viral transmission dynamics. "The distinction between virus vectors is crucial; it explains why certain viruses are not transmitted across different species, such as mosquitoes and ticks," Dr. Jose elaborated.

As a next step, the research team plans to investigate the factors influencing viral transmission more extensively, which could lead to breakthroughs in preventative measures against POWV infections. The implications of their findings extend beyond POWV, potentially informing vaccine development strategies for other tick-borne viruses.

Research funding was provided by the National Institutes of Health and the U.S. Department of Agriculture, highlighting the collaborative effort across institutions to tackle this emerging public health threat. The full research article can be found in the journal *Science Advances*, with further details on the study methodology and findings available for public access.

In conclusion, the mapping of the Powassan virus structure not only contributes to the scientific understanding of tick-borne viruses but also holds promise for future therapeutic interventions aimed at preventing the health complications associated with POWV infections. As tick populations continue to thrive in new regions, this research underscores the importance of ongoing vigilance and research in the field of infectious diseases.