The United States experienced a significant rise in influenza cases throughout December, following the most severe flu season since 2018, according to the Centers for Disease Control and Prevention (CDC). As of December 20, 2025, there were an estimated 7.5 million influenza cases and 81,000 hospitalizations, reflecting a 25% increase in cases compared to the previous week. With over 3,100 fatalities attributed to the virus in the year ending August 2025, public health officials stress the importance of vaccination.
In light of the rising cases, epidemiologist Jennifer Nuzzo from Brown University advises those who have not yet received a flu vaccine to do so as soon as possible, particularly vulnerable groups such as young children and older adults. “Bottom line for people, if they haven’t gotten vaccinated against the flu, they should get vaccinated,” Nuzzo stated.
Concerns Over Vaccine Uptake and New Variants
The surge in influenza cases follows a particularly severe flu season in 2024-2025, during which the CDC reported 279 influenza-associated pediatric deaths, the highest number recorded during a seasonal epidemic. This year, a new variant known as subclade K has emerged, coinciding with early flu season activity across Europe, which has seen “high or very high influenza activity” in December.
As reported by the CDC, approximately 130 million flu vaccines had been distributed in the US by the beginning of December, which is 13 million fewer than the same time last year. Concerns are mounting that fewer individuals will opt for vaccination following the cancellation of the CDC’s campaign to promote flu shots, led by health secretary Robert F. Kennedy Jr..
“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,” Nuzzo remarked.
Public Awareness and Treatment Options
Public awareness regarding flu testing and treatment may also be lacking. Nuzzo highlighted that residents can obtain at-home flu tests from pharmacies, which can be critical for timely treatment. “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 added.
Despite concerns over the effectiveness of the current vaccine against the new variant, Nuzzo noted, “It may protect you less, but it’s likely still going to give you some important protection.” As the flu season progresses, health officials continue to monitor the situation closely, urging the public to remain vigilant.
As the situation evolves, the CDC and various health experts emphasize the importance of preventive measures, including vaccination, to mitigate the impact of the ongoing flu season.
