The United States has experienced a notable increase in influenza cases during December 2025, following what has been described as the most severe flu season since 2018. According to the Centers for Disease Control and Prevention (CDC), the rise in cases raises concerns about the potential for a challenging flu season ahead.
While it remains uncertain whether the total number of flu cases will increase throughout the season or if the rise is simply concentrated in December, the CDC reported that more than 3,100 people died from influenza in the year ending August 2025. Health professionals stress the importance of vaccination, particularly for vulnerable populations.
Jennifer Nuzzo, an epidemiologist at Brown University, emphasized the need for those who have not yet received a flu vaccine to do so, particularly for young children and older adults. “Bottom line for people, if they haven’t gotten vaccinated against the flu, they should get vaccinated,” she stated.
Emerging data indicates that the current flu season has already seen significant impact. By December 20, 2025, there were an estimated 7.5 million influenza cases and 81,000 hospitalizations reported, marking a 25% increase in cases compared to the previous week. Thirty-two states have reported “high or very high” levels of flu illnesses, which poses a logistical challenge for healthcare facilities.
Concerns Over Vaccine Uptake and New Variants
The uptick in flu cases follows a particularly severe 2024-2025 flu season, which included 279 influenza-associated pediatric deaths, the highest number documented during a seasonal influenza epidemic. The emergence of a new variant, subclade K, has contributed to heightened concerns, particularly as the flu season commenced earlier than usual in Europe, where “high or very high influenza activity” was reported in December.
Nuzzo expressed apprehension regarding the potential impact of reduced vaccination rates this year. At the beginning of December, approximately 130 million flu vaccines had been distributed in the U.S., which is 13 million fewer than the same period last year. “It’s completely incredulous to me that after experiencing the worst flu season for kids on record, we could head into this season without a robust plan to encourage vaccination,” she noted.
The recent decision by the CDC, led by Robert F. Kennedy Jr., to cancel its campaign promoting flu vaccinations has raised further concerns about public health messaging. As the flu season progresses, the effectiveness of the vaccine against the new variant remains uncertain. Nuzzo indicated that while there might be a decrease in protection, individuals should still seek vaccination as it can offer significant benefits.
Access to Testing and Treatment
As the flu spreads, many may not realize that at-home tests are available at pharmacies. Nuzzo highlighted the importance of early treatment for those who test positive. “There are some people who might benefit from medication if they tested positive, but that medication needs to be given very soon after symptoms start,” she advised.
The current flu season underscores the critical need for public awareness regarding vaccination and treatment options. With the holiday season approaching, health officials urge individuals to take preventive measures to protect themselves and those around them.
