The United States has experienced a notable increase in influenza cases during December, following the most severe flu season since 2018. The Centers for Disease Control and Prevention (CDC) reported that over 3,100 people died from the virus in the year ending August 2025. The current spike raises concerns about the overall flu season, as it remains unclear whether the increase indicates a surge in total cases or simply a clustering of illnesses in December.
According to Jennifer Nuzzo, an epidemiologist at Brown University, it is critical for individuals who have not yet received a flu vaccine to do so promptly. “Bottom line for people, if they haven’t gotten vaccinated against the flu, they should get vaccinated, particularly young kids and older adults,” Nuzzo stated.
Impact of the Current Flu Season
The current flu season has already shown alarming trends. The 2024-2025 season was marked by the highest number of influenza-associated pediatric deaths since the CDC began tracking such data. A total of 279 pediatric deaths were reported, underscoring the potential severity of this year’s flu activity. The emergence of a new variant, subclade K, has also contributed to heightened concerns among health officials. In Europe, the flu season commenced earlier than usual, with regions reporting “high or very high influenza activity” in December.
In the United States, by December 20, 2024, there were an estimated 7.5 million influenza cases and 81,000 hospitalizations, reflecting a significant 25% increase in cases compared to the previous week. Thirty-two states reported a “high or very high” number of flu illnesses. Nuzzo emphasized the challenges posed by the current situation: “A lot of people are getting the flu at the same time, which is always tough. That is actually tougher than a situation in which people get it and it’s spread out over a longer period. It could be a worse season, in part because more people are going to need care than hospitals can easily deliver.”
Concerns Over Vaccination Rates
Compounding the situation is the concern that fewer individuals may choose to receive the flu vaccine this year. The CDC, under the leadership of Robert F. Kennedy Jr., has cancelled its campaign to promote flu vaccinations, which could further impact public health efforts. By early December, approximately 130 million flu vaccines had been distributed in the U.S., a decrease of 13 million compared to the same time last year.
Nuzzo expressed disbelief about the lack of a robust vaccination campaign given the previous year’s record-breaking flu season for children. “It’s completely incredulous to me that after experiencing the worst flu season for kids on record that we could head into this flu season – with signs that it could be bad, based on the viruses circulating out there – with anything but a robust plan to encourage people to get vaccinated,” she said.
Furthermore, there is uncertainty regarding the effectiveness of the current vaccines against the new variant. Nuzzo noted, “We have some reason to think that the protection may be lower, but I want to be careful by saying that. It may protect you less, but it’s likely still going to give you some important protection.”
Additionally, many individuals may not be aware that at-home flu tests are available at pharmacies. Nuzzo highlighted the importance of these tests, stating, “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.”
As the flu season progresses, public health officials stress the importance of vaccination and awareness in mitigating the impact of this year’s influenza surge.
