As the holiday season came to a close, U.S. flu infections have surged, prompting health officials to declare this a severe flu season that is likely to worsen. Recent government data released on Monday, which covers flu activity through the week of Christmas, indicates that this year's flu season is already exceeding the severity of last winter's flu epidemic, regarded as one of the harshest in recent history.
According to reports, during the week of Christmas, 45 states experienced high or very high levels of flu activity, a significant increase from 30 states the previous week. Public health experts attribute this rise in flu cases to a particular strain of the virus that has been spreading. The H3N2 flu virus, known for causing the most hospitalizations and fatalities among older adults, has been the most frequently reported type this season.
Even more concerning is the emergence of the subclade K variant of the H3N2 virus. Current analyses show that over 90% of H3N2 infections are linked to this new variant, which differs from the strain included in this year's flu shots. With flu seasons typically peaking in January or February, it remains uncertain how this mismatch will impact the overall flu season.
Dr. Robert Hopkins, the medical director of the National Foundation for Infectious Diseases, expressed concern about the consistent rise in flu cases over recent weeks, indicating that the peak of the flu season may still be ahead. The previous flu season saw record-high hospitalization rates, the worst since the H1N1 pandemic 15 years ago, and a staggering 288 child flu deaths were reported.
This flu season has already recorded nine pediatric deaths, and the proportion of emergency department visits for flu-related issues among children has already exceeded the peak levels seen during the 2024-2025 flu season. Dr. Hopkins noted that while H3N2 primarily affects older adults, the increasing rates among children and young adults suggest that this flu season could impact all age groups severely.
Although deaths and hospitalizations have not yet reached the high levels seen in the previous year, Dr. Hopkins cautioned that these are often lagging indicators. The Centers for Disease Control and Prevention (CDC) estimates that there have already been at least 11 million flu illnesses, 120,000 hospitalizations, and 5,000 flu-related deaths this season.
In light of these developments, public health experts continue to recommend that everyone aged six months and older receive an annual influenza vaccine. However, the federal health officials announced on Monday that they would no longer recommend flu vaccinations for U.S. children, stating that this decision should be made in consultation with healthcare providers. Despite this change, flu vaccines will still be fully covered by private insurers and federal programs, such as Medicaid and the Vaccines for Children program.
In addition to the flu, COVID-19 infections have also been rising, though they remain less prevalent than flu cases this winter. Notably, the Trump administration had previously stopped recommending COVID-19 vaccinations for healthy children last year.
Dr. Hopkins raised concerns about a recent federal notice stating that Medicaid programs, which provide medical services for low-income families, will no longer be required to report immunization rates. While CDC survey data suggests that flu vaccination rates are similar to last year's, the Medicaid data offers a more comprehensive view of vaccination among children at higher risk for various diseases.
Health Secretary Robert F. Kennedy Jr. framed the decision as a way to separate how Medicaid doctors are rated and compensated from vaccination practices. However, Dr. Hopkins emphasized that this change could eliminate crucial data that communities rely on to evaluate their efforts to protect children from vaccine-preventable diseases, calling it a disastrous plan.