Flu is surging around the country, and Vermont is not immune to the national trend, though the federal Centers for Disease Control and Prevention’s most recent dashboard for the disease identifies the state’s illness prevalence as lower than much of the U.S.
In Vermont, about 20-25% of tests have come back positive this season, according to a state dashboard with data through Jan. 3.
Statewide, nearly 8% of visits to a Vermont emergency room or urgent care were due to flu-like illnesses; nearly 6% were related to diagnosed flu cases, according to the state data available through Jan. 3. Both rates were much higher than this same period last year.
The overwhelming majority of these tests have come back positive for one particular strain of influenza A, which is the most common of the four flu virus types. This year, a particularly vicious subvariant of that strain, subclade K, has dominated most flu cases across the country. While Vermont’s testing does not have that extra level of granularity, it’s likely these cases in the state are subclade K, said John Davy, the health surveillance epidemiologist at the Vermont Department of Health.
Experts are not yet sure whether this strain is so prevalent due to the fact that it spreads more easily or due to it being more dangerous. But it’s clear that the illness has been especially brutal this season: In New York, the state has had the highest number of flu cases ever reported in a single week. In Connecticut, doctors told a local news outlet that the surge is the highest they’ve ever seen.
At UVM Medical Center, the illness prevalence mirrors statewide numbers, confirmed Phillip Rau, a spokesperson for the Burlington hospital. That is starting to trend downward, Rau added, though Vermont’s flu season generally lasts into late March.
The hospital currently has around 20 people admitted with the flu or related health concerns, he said.
Rutland Regional Medical Center, the state’s second largest hospital after UVM Medical Center, is seeing a much earlier spike in cases than in years past. In December, the hospital had 106 positive flu cases, compared with just 17 in December 2024, according to the hospital’s spokesperson Gerianne Smart.
As of Jan. 13, the Rutland hospital has confirmed 88 cases of flu this month so far, while last January there were 125 cases the entire month.
Smart said this early surge may be due to the fact that more severe symptoms lead people to seek out care.
Wastewater testing — done at six sites in Vermont — also shows flu increasing in the state. The most recent reports show “high” levels of flu in wastewater, though earlier in December levels were “very high.” Montpelier and Burlington sites show a higher concentration of the illness than the Ludlow and Middlebury sites.
Davy, at the health department, explained that it’s important to assess all of these available data points together. “Each has its kind of strengths and weaknesses, reflecting a slightly different sort of phenomenon on the ground,” he said.
He said that the reason the CDC’s dashboard may show lower rates in Vermont than in neighboring states may be due to differences in how each state calculates and reports flu occurrence and may be because Vermont’s smaller population makes the data more responsive to smaller shifts in behavior — like a dip in the number of people seeking care over the holidays.
It doesn’t mean that there’s a shortage of flu in the state. He pointed to the outbreak reports that the health department receives from institutions — places like schools and nursing homes. Those show a growing number of flu cases, which he said can be a useful indicator for the rest of the state.
Over one-fifth of patients with flu-like illness in Vermont are children under 5 years old, according to the state data from Dec. 28 to Jan. 3 — a “big, disproportionate amount,” compared to the state’s population that age, Davy said.
“These are populations where vaccination can have a really positive impact,” Davy said.
The variant arose this summer, and thus was not incorporated as a reference strain in this year’s flu vaccine, though early research from England shows this year’s shot does convey some immunity.
“Subclade K may be more likely to evade a vaccine, but folks’ immune systems are still going to benefit,” Davy added. “It could mean the difference between a real severe illness that you spread to a lot of people and a more minor illness that you’re less likely to spread.”
In Vermont, only 32% of the population, or around 208,000 people, have received the flu vaccine so far this season, according to a state dashboard.
The surge comes in the midst of changing guidelines from the CDC surrounding childhood immunization, including a demotion of the flu vaccines from something the federal body recommended for all children, to an immunization it recommended only after children or their guardians discuss with a doctor. Last week, Vermont state health officials held firm to their existing guidelines recommending that all children receive the vaccine against flu.
Davy noted that the majority of flu deaths each year are children who did not receive the flu vaccine.
On top of vaccination, Davy recommended individuals protect themselves and others from flu by practicing familiar safety measures against respiratory illnesses: stay home if you’re sick, wear a mask in crowded areas and wash your hands often.
