The United States is experiencing a significant surge in flu activity, with health officials characterizing the 2025-2026 season as severe and likely to worsen. Recent government data indicates that flu activity through the week of Christmas saw 45 states reporting high or very high levels, a substantial increase from previous weeks. This season's severity is reportedly surpassing the flu epidemic of last winter, which was one of the harshest in recent history. The heightened activity is primarily attributed to the Influenza A H3N2 virus, specifically a new version known as the subclade K variant. This particular variant differs from the strain included in this year's flu shots, leading to concerns among public health experts regarding a potential vaccine mismatch. Despite this, health professionals still recommend vaccination, as it can help prevent hospitalizations and reduce severe illness. Nationally, the Centers for Disease Control and Prevention (CDC) has reported approximately 11 million illnesses, 120,000 hospitalizations, and 5,000 deaths from the virus so far this season. The term 'super flu,' which has appeared in some news reports, is largely considered colloquial rather than a scientific descriptor. Dr. Andrew Pavia, a pediatric infectious disease expert, has debunked the myth, clarifying that while the circulating strain is concerning due to vaccine effectiveness, there is nothing inherently 'super' about it in medical terms. The surge has led to high hospitalization rates, with children and older adults being particularly vulnerable. While Utah, for example, is experiencing its highest hospitalization rates this decade, doctors emphasize the importance of vaccination and early treatment with antiviral medications.