A new and potentially more severe variant of the flu , known as H3N2 subclade K, has reached the United States, prompting heightened vigilance from public health officials as the holiday season and winter travel approach. According to the Centers for Disease Control and Prevention's ( CDC ) flu report, there have already been at least 650,000 illnesses, 7,400 hospitalizations, and 300 deaths from flu this season, ending the week of November 15. Among the cases reported nationwide last week, 71.