For Tick-borne flaviviruses like Powassan virus, vector specificity and tropism are poorly understood and there are no vaccines available to prevent infections. I investigate the role of Powassan virus Envelope (E) protein, crucial for viral entry and vector specificity. I successfully constructed cDNA clones and generated chimeric Yellow Fever-Powassan virus. My experiments show these chimeras are efficient BSL-2 model systems to study the role of E protein in virus entry, receptor interactions, and vector specificity.