As the U.S. flu season begins at a slower pace than usual, new data from the Centers for Disease Control and Prevention (CDC) has identified a recently emerged variant of the virus driving current infections.

Preliminary findings indicate that this new strain-belonging to the type A H3N2 family, which is historically associated with more severe illness and increased hospitalizations, especially among older individuals-may still be partially covered by existing flu vaccines.

Health experts are expressing concern about lagging vaccination rates. This issue played a major role in last winter’s exceptionally severe flu season, one of the deadliest seen in recent decades.

“I think we’re going to see a really severe season,” warned Asefeh Faraz Covelli of George Washington University’s School of Nursing.

Last year saw the highest rate of flu-related hospital admissions since the 2009 H1N1 pandemic. More than 18,000 deaths were attributed to influenza, including one week early in the year that recorded over 1,800 fatalities-the most for any single week in at least ten years. Pediatric deaths from flu also exceeded average figures.

So far this season, overall flu activity remains low across most of the country. According to CDC influenza surveillance lead Alicia Budd, only Louisiana has reported moderate levels of infection.

The majority of cases have been detected among children and involve a newly identified H3N2 subclade called "variant K," which differs genetically from the strain included in this year’s vaccine formulation.

An early study conducted in the United Kingdom indicates that while protection may not be complete, this season’s vaccines appear to provide at least some defense against variant K; however, researchers emphasize that more evidence is required.

Flu cases typically surge between December and February. Health officials anticipate an increase as families travel and gather for Thanksgiving celebrations later this month.

"This is the ideal time to get vaccinated," Covelli advised.

The CDC’s ability to monitor respiratory illnesses faced additional challenges when a recent government shutdown briefly interrupted data collection just as seasonal infections began their usual climb.

The scope of vaccine outreach efforts has also narrowed following changes in federal health leadership. Since Health Secretary Robert F. Kennedy Jr.-a long-standing critic of vaccines-assumed oversight of agencies such as the CDC, his public remarks questioning vaccine safety have added confusion around immunization campaigns.

COVID-19 vaccination coverage continues to decline nationwide: only about six percent of children and fourteen percent of adults are currently up-to-date on shots-a decrease compared to last autumn’s rates.

Flu vaccination patterns show mixed signals. Data from IQVIA indicates that pharmacies have given out over two million fewer doses than at this point last year. However, CDC surveys show steady childhood vaccination rates holding at thirty-four percent and adult rates increasing slightly to thirty-seven percent.

It remains uncertain whether these trends will persist through the remainder of flu season, according to CDC officials.

As November began, hospitalization rates related to influenza in the U.S. roughly matched those seen at this time last year. Hospitalizations for COVID-19 and RSV remain below figures reported during last year’s comparable period.