Rare tick-borne virus turns deadly fast as US cases reach record high, experts warn By Latest & Breaking News on Fox News Comments Off on Rare tick-borne virus turns deadly fast as US cases reach record high, experts warn 2 Min Read Powassan virus, a rare tick-borne illness traced to a 1958 case, has hit record highs in 2025, with 76 U.S. diagnoses and no vaccine available.