Health Experts Warn of Early Flu Surge Driven by New H3N2 Strain:

As flu season ramps up, health officials worldwide are expressing growing concern over a new strain of influenza that has emerged in recent months — too late to be included in this year’s flu vaccines. The strain, a variant of H3N2, first appeared in June, four months after the formulation of the Northern Hemisphere’s flu shots had been finalized. Since its emergence, the virus has spread rapidly, causing early outbreaks in countries such as Canada and the U.K., where hospitals are already seeing rising admissions. “Since it emerged, it’s rapidly spreading and predominating in some countries so far in the Northern Hemisphere,” said Dr. Wenqing Zhang, head of the World Health Organization’s Global Respiratory Threats Unit, during a media briefing. According to Antonia Ho, an infectious disease consultant at Scotland’s University of Glasgow, this H3N2 variant has acquired seven new mutations over the summer. “That means the virus is quite different from the H3N2 strain included in this year’s vaccine,” she explained. In the U.K., officials are bracing for what could be a particularly severe winter. James Mackey, head of the National Health Service, warned last week that flu cases could be triple the number seen at this time last year. Similarly, Canada is reporting a noticeable uptick in cases, and Japan is experiencing an unusually early and intense flu season. In Tokyo alone, flu cases as of November 4 had surged to nearly six times the level seen at the same time last year, according to the Japanese Ministry of Health, Labor and Welfare. More than 2,300 day cares and schools have been partially closed due to outbreaks, reports Nippon TV. “These are not good signs,” noted Angela Rasmussen, a virologist at the University of Saskatchewan. Is H3N2 Already in the U.S.? H3N2 is a type A influenza virus, which tends to cause more severe illness, especially in older adults. While anecdotal reports suggest flu A is circulating in parts of the U.S., detailed national data remain sparse. The Centers for Disease Control and Prevention (CDC) has not released an updated report on flu activity since September 26, due to the government shutdown. Even after reopening, the CDC faces challenges in tracking flu activity, as recent public health workforce cuts have reduced the agency’s capacity for comprehensive data collection. “We are going to be dependent on state laboratories and academic labs for these investigations and reporting,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center. “The information will not be as centralized or quickly analyzed as in previous years.” Will This Year’s Flu Shot Help? Each year, health authorities and vaccine manufacturers select flu strains for the Northern Hemisphere vaccine based on patterns observed in the Southern Hemisphere. This year’s shot targets three strains: two influenza A types and one influenza B type. While the vaccine does not entirely prevent infection, it significantly reduces the severity of illness. Last year, flu shots were up to 55% effective at keeping adults out of the hospital. Preliminary data from the U.K. indicate that this year’s vaccine is about 40% effective at preventing hospitalization in adults. Experts still strongly encourage vaccination. “All of the data over previous decades show that even if there is not a close match, use of the vaccine continues to prevent hospitalizations, ICU admissions, and deaths,” Schaffner said. With the flu season arriving early and an H3N2 strain spreading quickly, health officials are urging everyone — especially older adults and those with underlying conditions — to get vaccinated and take precautions to limit transmission. While the season may be severe, the vaccine remains a critical tool in preventing serious illness and saving lives.

HEALTH