Dec 9, 2025 By Karen Mansfield 3 min read

Associated Press

The annual flu vaccine is recommended for everyone 6 months of age and older, with few exceptions

As Pennsylvania heads into flu season, a new – and potentially severe – influenza variant has been sweeping across the United States, causing concern for the winter months.

The strain is called subclade K, and it has made its way to the U.S. after causing a surge in cases through countries including Canada, the United Kingdom, and Japan.

It is a mutated variant of influenza A’s H3N2 subtype, which has historically caused more hospitalizations and deaths in older people and those with health concerns than other strains.

“There is a different strain, the H3N2, that is dominant and has shown to be potent in intensity, especially in older people. People getting the flu are sicker,” said Dr. Sundeep Ekbote, an emergency medicine physician at Penn Highlands Mon Valley Hospital.

With the spread of the new strain, and fewer people getting vaccinated, the flu season could be rough.

While the new variant – which emerged too late for it to be incorporated into the current flu vaccine – may render this year’s flu shot less effective, doctors still urge Pennsylvanians to get vaccinated to limit severe illness and prevent outbreaks.

“Even though this year’s shot is not quite a direct match for the H3N2 strain, it can help decrease the intensity of the flu and the spread of influenza,” said Ekbote.

Symptoms for H3N2 are similar to other flu strains, but can be more intense for some groups, including children, adults over 65, and those with chronic medical conditions like asthma or heart disease.

Those symptoms include fever, cough, runny nose, and possible gastrointestinal issues such as vomiting or diarrhea.

So how can people project themselves? The top recommendation is to get vaccinated for the flu, to limit severe illness and prevent outbreaks.

Ekbote also recommended wearing masks in indoor spaces and washing hands to help reduce the likelihood of infection.

During the 2024-25 respiratory virus season, the Pennsylvania Department of Health recorded 234,276 confirmed cases, 40,387 hospital admissions, and 1,049 flu-related deaths. Additionally, 280 children across the United States died from influenza during the 2024-25 flu season, half of whom did not have an underlying medical condition.

The flu season in Pennsylvania runs generally from October to April.

Currently, Pennsylvania is experiencing low flu activity in most areas of the state, but as holiday gatherings continue in December, there’s a risk of a bigger jump in cases.

“We haven’t seen a whole lot (of flu cases) yet. By this time last year, we had 10 times as many cases compared to this year,” said Ekbote. “Up until now, we haven’t seen as much flu, but it will catch up.”

Everyone 6 months and older is recommended to get a flu shot.

As of the end of November, an estimated 40% of adults in Pennsylvania had received the flu shot.