New flu strain drives surge in US cases; experts warn season far from over, 18 million affected

Flu activity in the United States appears to have eased slightly after weeks of intense spread, but health officials caution that the season is far from over. Newly released data from the Centers for Disease Control and Prevention shows that at least 18 million Americans have fallen ill with influenza so far in the 2025–26 season, with 230,000 hospitalisations and 9,300 deaths attributed to the virus. Fourteen states are reporting “very high” levels of flu‑like illness, while 19 states are seeing “high” activity, ABC News reported.In the week ending January 10, at least 15 flu‑associated deaths were recorded among children, bringing the total paediatric toll to 32. Last season saw a record 289 children die from flu, the highest since the CDC began tracking in 2004, making this season’s child fatalities a significant concern. Among children whose vaccination status is known, 90 % of deaths occurred in those not fully vaccinated against influenza.Recent government data cited by news agency AP indicates that several measures of flu activity have declined for two consecutive weeks. There has been a notable drop in hospitalisations and a smaller but significant decrease in visits to medical offices for flu‑like illness. The number of states reporting high flu activity has fallen from 44 to 36. COVID‑19 and respiratory syncytial virus (RSV) have not seen large surges during the same period, and the CDC describes the overall respiratory virus season as “moderate.”However, experts cited by AP warn that a decline in certain indicators does not necessarily signal that the flu season has peaked. “We’ve had other seasons where we’ve had a peak, it’s gone down, but we’ve nonetheless had a prolonged season,” said Dr William Schaffner, an infectious diseases specialist at Vanderbilt University. “Most of us are crossing our fingers, but I don’t think we can rely on the concept that flu is abating very early this year.”The flu season has been dominated by the influenza A H3N2 virus, a subtype historically associated with more severe illness, especially among older adults and young children. Genetic analysis shows that the vast majority of H3N2 viruses circulating are part of a variant known as subclade K, which differs from the strain targeted by this year’s vaccine. This mismatch may reduce vaccine effectiveness against infection, though vaccination still provides protection against severe disease.Influenza, or flu, is a highly contagious respiratory infection that spreads quickly during winter months. Symptoms often strike suddenly, ranging from fever, cough and sore throat to body aches and extreme fatigue. In children, vomiting and diarrhoea are more frequently seen. Not all infected people develop fever, making early detection harder.Though many recover within days, flu can trigger serious complications including pneumonia and worsening of existing health conditions. Health authorities warn that older adults above 65, pregnant women, young children under five — particularly those below two — and people with chronic diseases such as asthma, diabetes and heart ailments remain the most vulnerable to severe illness.Doctors continue to urge all Americans aged six months and older to get vaccinated. “We’re still in the thick of flu season, so it’s not too late to get your flu shot,” said Dr Aaron Milstone, paediatric director of infection prevention at Johns Hopkins Health System told ABC News. “The goal of the flu vaccine is really to keep people out of the hospital and to keep them alive… it’s not 100 % effective at preventing infection, but hopefully it prevents complications that can lead to hospitalisation or death.”