New research indicates the current seasonal flu vaccine may be significantly more effective than experts initially feared, offering a glimmer of hope during what is being described as America's most severe influenza outbreak in more than two decades.
Unexpected Efficacy Against Evolving Strain
Scientists at the University of Pennsylvania have presented promising, though not yet peer-reviewed, findings. Their study analysed blood samples from 76 adults, aged between 24 and 81, before and after they received the flu shot. The results showed the proportion of individuals with antibodies capable of neutralising the predominant H3N2 strain, specifically the "subclade K" variant, surged from 39% to 71%.
Professor Scott Hensley, a microbiology expert involved in the research, called this "unexpected good news." He explained to NBC News that despite the vaccine not being a perfect match for the circulating virus, it appears to generate antibodies that should provide meaningful protection against severe illness.
A Nation Gripped by Severe Outbreak
This scientific insight arrives amidst a devastating flu season across the United States. Cases have hit high or very high levels nationwide this winter, leading to an estimated 15 million illnesses, 180,000 hospitalisations, and 7,400 deaths. The American Academy of Pediatrics has noted that nearly every state is experiencing intense respiratory illness activity.
This season is on track to be the worst in over 25 years, with symptoms reportedly more severe and including prolonged fevers and increased gastrointestinal issues. Tragically, the threat to children remains acute. The previous 2024-2025 season saw nearly 290 pediatric flu deaths, and this season has already claimed young lives, including two-year-old Isaias Castillo IV from New Jersey.
The Critical Importance of Vaccination
Despite the concerning figures, only about 130 million people—less than 40% of the US population—have been vaccinated this season. For children, the vaccination rate stands at approximately 42%. Research from the Centers for Disease Control and Prevention (CDC) indicates that last year, 89% of children who died from flu were not fully vaccinated.
Experts are urging the public not to delay, stressing it is not too late to get protected. "The implications are clear: go get this year's vaccine if you haven't already!" Professor Hensley emphasised. Flu seasons typically peak between December and February but can persist until May, and there is no clear sign the current wave has reached its zenith.
The call for vaccination comes even as the CDC recently announced an overhaul of the childhood vaccine schedule, which included removing universal flu shot recommendations—a move criticised by some health leaders as "tone deaf" during such a severe outbreak.
