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Now is around the time when flu season usually starts to pick up — except this year, cases have been rising since late summer.
Some data shows current flu activity is similar to when flu activity peaks at the end of the year. But it’s still too early to tell whether this year’s flu will be particularly severe.
For now, experts are warning people take precautions: Avoid people who are sick, wash your hands — and get vaccinated.
This year, there’s a brand new shot that takes a totally different approach to flu prevention, and early data shows it’s more effective than the traditional shot. But it’s not for everyone.
Here’s what to know.
Rising flu cases
October is the typical start of the flu season. But this year, cases started rising as early as late August. Based on wastewater data, flu activity reached levels this month usually not seen until December or January — when flu season historically peaks.
“Early-season influenza activity is currently higher than typically observed at this time of year,” the CDC said.
That said, a vast majority of the country remains in “minimal” range of flu cases.
“Every influenza season is different — some begin earlier than usual, others later,” the CDC said. Despite an early start to flu season, 2026’s flu trends remain “within expected seasonal variation.”
And while the flu generally starts picking up in southern states, this year, it appeared first in the West: California, Washington, Hawaii and Alaska. Some experts say these changes might point to an evolving flu virus.
‘Stick’ season
An earlier flu season means considering getting an earlier flu shot, experts say. And this year, there’s a brand new one on the market.
In August, the FDA approved mFLUSIVA, the first mRNA flu vaccine for adults aged 50 and older.
Unlike traditional flu vaccines, it does not contain a weakened or inactive flu virus. Instead, it works by giving instructions via mRNA to your immune cells on how to kill the flu virus on its own.
This is the same technology used in the COVID-19 vaccines.
“There is some evidence that suggests mFlusiva may offer somewhat better protection against the flu than traditional flu vaccines,” Dr. Rebecca Choudhury, an infectious disease doctor at Mount Sinai, said.
In adults 50 and older, the mRNA vaccine had a 27% lower rate of flu infection compared to traditional vaccines. Adverse reactions to the new vaccine were very rare, and happened at similar rates to side effects to the traditional flu vaccine.
Choudhury says adults aged 50 to 64 have the clearest reason to consider it, and especially those with chronic health conditions that raise the risk of a severe case of flu.
That said, it’s a very new drug that may not be available at every doctor’s office or pharmacy — and Choudhury says it’s better to get the traditional shot rather than go without.
Everyone six months and older should get an annual flu shot, the CDC says. This year’s traditional flu vaccines target three flu viruses — H1N1 and H3N2 (both subtypes of the more common influenza A) and influenza B.
According to CDC data, over 75% of positive flu tests are H1N1 for the last month. It’s been circulating since it emerged as “swine flu” in 2009 and has become a regular part of flu season, joining a number of other influenza A and B strains that come back every year.
This year’s vaccine was adjusted to protect against a H3N2 mutation called “subclade K” that spread widely last year. This type of flu causes typical flu symptoms like fever and cough to come on more abruptly.