The United States is experiencing a significant increase in influenza cases this December, following the most severe flu season since 2018. According to the Centers for Disease Control and Prevention (CDC), over 3,100 people died from the flu in the year ending August 2025. This rise in cases has prompted health experts to urge individuals who have not yet received a flu vaccine to do so, especially vulnerable populations such as young children and older adults.
The current flu season began earlier than usual, with a new variant identified as subclade K contributing to the surge. By December 20, 2025, the CDC reported approximately 7.5 million influenza cases and 81,000 hospitalizations in the US. This represents a staggering 25% increase in cases compared to the previous week. Thirty-two states reported a “high or very high” level of flu illnesses, highlighting the widespread nature of the outbreak.
Health Experts Urge Vaccination Amid Rising Cases
Jennifer Nuzzo, an epidemiologist at Brown University, emphasized the importance of vaccination during this critical period. “Bottom line for people, if they haven’t gotten vaccinated against the flu, they should get vaccinated, particularly young kids and older adults,” she stated. Nuzzo expressed concern that many individuals may not seek vaccination due to the cancellation of the CDC’s campaign encouraging flu shots, led by health secretary Robert F. Kennedy Jr..
At the start of December, approximately 130 million flu vaccines had been distributed in the US, which is 13 million less than the same time last year. Nuzzo noted the significance of this decline, especially after a 2024-2025 flu season that recorded the highest number of pediatric deaths associated with influenza. “It’s completely incredulous to me that after experiencing the worst flu season for kids on record, we could head into this flu season with anything but a robust plan to encourage people to get vaccinated,” she remarked.
Concerns Over Vaccine Effectiveness and Access to Treatment
As health officials monitor the situation, there are concerns regarding the effectiveness of the current flu vaccines against the new variant. Nuzzo indicated, “We have some reason to think that the protection may be lower.” Nevertheless, she reassured that the vaccine would still likely offer important protection.
Additionally, Nuzzo highlighted the availability of at-home flu tests at pharmacies, which can be crucial for those who test positive and may require antiviral medications. “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 rapid increase in flu cases poses a challenge for healthcare systems, which may struggle to manage a sudden influx of patients. Nuzzo warned that a concentrated spike in cases is often more difficult to handle than a gradual spread over time. “It could be a worse season, in part because more people are going to need care than hospitals can easily deliver,” she explained.
As influenza cases continue to rise, public health officials are urging everyone to remain vigilant and consider vaccination as a vital step in protecting themselves and their communities during this challenging flu season.