Flu FAQ: Is the flu worse this year? Here’s what you need to know
U.S. health officials are reporting an early and widespread flu season. The Centers for Disease Control and Prevention (CDC) estimated there have been more than 4.5 million cases nationwide and 49,000 flu-related hospitalizations. Nearly 2,000 people have died from the flu so far this season, including at least three children.
This time last year, the agency estimated there had been 1.9 million cases with 23,000 hospitalizations and 970 deaths, including four pediatric deaths.
Some media outlets have dubbed this year’s virus the “superflu.” This is not a scientific term and may be misleading. While flu cases are peaking earlier than usual, there is no evidence suggesting this year’s flu season is more severe than previous years. However, the number of people in the U.S. being vaccinated for the flu declined in recent years, and preliminary analysis suggests that vaccination rates are set to drop even lower this year.
Are we facing a ‘superflu’?
The dominant version of the virus currently spreading is called H3N2 subclade K; it is a newly emerged subclade — or subgroup — of a common flu strain that has plagued humans for decades. This new subclade is behind an earlier-than-usual surge of flu cases in the U.S., as well as Japan, the U.K. and other parts of Europe, where the flu season started four to five weeks earlier than usual.
When a new version of the flu — such as subclade K — emerges, there is always a chance the virus is so different from other versions that it bypasses existing immunity from previous infections or vaccines. So far, there is no evidence that subclade K is doing this.
U.K. health officials analyzed preliminary flu data and predicted that subclade K may spread more easily than other versions. The researchers estimated that the reproduction number of subclade K is 1.4, meaning that each infected person spreads the virus to 1.4 other people on average. Typically, the reproduction number of the flu is closer to 1.2.
While this difference may seem small, it could translate into tens of thousands of additional flu cases. If 1 million people are currently infected with the flu, then, on average, they would infect 1.4 million other people. At the lower reproduction number, those one million infected people would only have infected 1.2 million people. That’s a difference of 200,000 flu cases.
While there will be more flu cases this year, so far, there is no evidence that this new flu version will cause more severe cases, hospitalizations or deaths. Health officials have already recorded many more cases this year than at the same time last year, about 4.5 million cases compared to 1.9 million in 2024. But of those nearly two million cases last year, 1.2% were hospitalized and 0.05% died from their infections. So far in 2025, the rate of hospitalization is 1.09% and the mortality rate is 0.04%.
The World Health Organization reported that this strain is not causing more severe disease than previous strains. The CDC described the current flu season as “low severity” across all ages.
Flu shots and side effects
H3N2 subclade K emerged this summer, months after U.S. health officials and vaccine makers finalized this year’s flu vaccine formula. The CDC has not yet commented on the effectiveness of this year’s flu vaccine in the U.S. But U.K. health officials previously estimated that their vaccine, which is different from the one used in the U.S., reduced hospitalizations by about 70-75% in kids and by about 30-40% in adults.
Even if the flu vaccine does prove effective, vaccination rates have been declining since the COVID-19 pandemic. During the 2023-24 flu season, about 55% of children and 45% of adults received at least one dose of the flu vaccine, down from 64% and 48% during the 2019-20 season.
Vaccination rates are on track to be lower this flu season than last. Just over 26 million flu shots have been administered so far this year at retail pharmacies across the U.S., about 2 million fewer than this time last year, according to analysis by IQVIA, a health and science research company.
The CDC recommends that most people aged 6 months and older receive an annual flu vaccine. However, vaccine manufacturers projected they would supply only about 154 million doses to the U.S. for the 2025-2026 flu season, which is not enough to cover the nation’s entire adult population.
The post Flu FAQ: Is the flu worse this year? Here’s what you need to know appeared first on Straight Arrow News.
Ella Rae Greene, Editor In Chief
