Across the United States, influenza cases have shown a small reduction last week according to newly released government figures, but health officials emphasize uncertainty about whether the peak of this severe flu season has been reached. Data updated on Friday tracks flu activity through the previous week, indicating a decrease in outpatient visits for flu-like symptoms and a slight reduction in the number of states reporting widespread flu incidence.
Despite these signs of decline, multiple indicators point to this season surpassing the severity witnessed during the last winter's flu epidemic, which was among the most intense in recent memory. Experts anticipate ongoing difficulties ahead. Dr. James McDonald, New York State Health Commissioner, remarked, "This is going to be a long, hard flu season," highlighting the sustained impact expected in the coming weeks.
The predominant circulating influenza strain this season has been A H3N2. This strain historically accounts for the highest rates of hospitalizations and fatalities among older adults. Alarmingly, over 91% of the analyzed H3N2 infections belong to a new subvariant called the K variant, which differs from the strain included in the current seasonal vaccines, raising concerns about vaccine effectiveness.
Last year's flu season recorded the highest overall hospitalization rate since the H1N1 pandemic fifteen years ago. Child mortality linked to influenza reached 289, marking the deadliest pediatric flu season in the 21st century, surpassing even the 2009-2010 "swine flu" pandemic toll.
To date, the Centers for Disease Control and Prevention (CDC) estimate that this season has resulted in approximately 15 million flu illnesses and 180,000 hospital admissions. The death count is estimated at 7,400, including at least 17 pediatric fatalities.
As of last week, 44 U.S. states reported high flu activity levels, representing a slight decrease from prior weeks. However, hospitalizations and deaths related to the flu have increased. Assessing flu season trends over the holiday period presents challenges due to school closures, travel, and varying healthcare-seeking behaviors. Some individuals may choose to manage symptoms at home, while others opt for medical consultation.
Flu seasons historically can exhibit multiple waves—initial surges followed by declines and subsequent spikes. For years, federal health authorities have advised annual influenza vaccination for everyone older than six months to mitigate severe outcomes, even if the vaccine does not entirely prevent infection.
However, this year, federal officials have shifted guidance by no longer endorsing universal flu vaccination for U.S. children, advising families to discuss vaccination decisions with their healthcare providers. This change has raised concerns among advocacy groups. Michele Slafkosky, executive director of Families Fighting Flu, expressed profound alarm, stating, "I can’t begin to express how concerned we are about the future health of the children in this country, who already have been unnecessarily dying from the flu—a vaccine preventable disease." She warned that ensuing confusion over vaccine guidance could result in more severe impacts in future flu seasons, especially for young, vulnerable populations.
Influenza is part of a group of respiratory viruses that tend to increase in prevalence during colder months. Recent weeks have also seen rises in hospitalizations associated with COVID-19 and respiratory syncytial virus (RSV), although these are not as commonly diagnosed compared to flu infections based on federal data.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. All content responsibility lies with the Associated Press.