Flu cases spiking this holiday season, CDC data shows

The latest data from the Centers for Disease Control and Prevention (CDC) reveals a concerning spike in flu cases across the United States, with some regions experiencing record numbers of flu-related illnesses. As of December 20, the CDC estimates that there have been approximately 7.5 million flu cases this season, along with 81,000 hospitalizations and 3,100 deaths. Tragically, there have been eight flu-related pediatric deaths reported.

According to the CDC, 32 jurisdictions are currently reporting “high” or “very high” levels of flu activity, a significant increase from just 17 jurisdictions the previous week. These jurisdictions include all 50 states, territories, the District of Columbia, and New York City.

In New York, the State Department of Health recorded a staggering 71,000 flu cases in one week, marking the highest number of cases ever reported since tracking began in 2004. Similarly, the Massachusetts Department of Public Health noted “high” flu activity, with Boston reporting a 114% spike in cases, particularly among children. In Minnesota, a surge in flu cases prompted a school to transition to online learning before the holidays, with 113 flu-related hospitalizations reported in 2025, more than double the previous year.

Experts are especially concerned about the prevalence of a new subtype of influenza A known as H3N2, which is spreading rapidly. Of the flu specimens tested between December 13 and December 20, the majority were influenza A, with nearly 92% identified as H3N2. Jesse Bloom, a scientist at the Fred Hutchinson Cancer Center, explained that this strain has evolved just enough to evade immune recognition, posing a greater risk to vulnerable populations, especially seniors.

Despite the severity of this year’s flu season, there has been a decrease in flu vaccination rates. The CDC reported that approximately 130 million doses of the flu vaccine have been administered nationwide. Richard Webby, director of the World Health Organization’s Collaborating Centre for Studies on the Ecology of Influenza in Animals and Birds, emphasized the importance of vaccination, noting that while there may be a mismatch with H3N2, the vaccine remains effective against other strains like H1N1 and flu B.

Early data from the United Kingdom suggests that flu vaccines are still effective in preventing severe illness, particularly in children. Bloom reiterated the importance of vaccination, stating that while it may not guarantee immunity, it significantly reduces the risk of infection, especially for high-risk individuals.

In conclusion, the current flu season poses significant challenges, with the prevalence of H3N2 and decreased vaccination rates contributing to the spike in cases. Despite these obstacles, experts emphasize the importance of vaccination as a crucial strategy in mitigating the risk of flu-related illnesses and complications.