Rough Flu Season May Lie Ahead

We could be facing a “severe” flu season in which the available vaccines offer limited protection, according to UVA's Frederick G. Hayden, MD, a professor emeritus at the School of Medicine.

The vaccines appear to be a poor match for the subclade K virus that is already circulating and is likely to spread further over the holidays and during the subsequent return to school, Dr. Hayden says in a new scientific paper.

The variant is of the same influenza A lineage that caused the flu pandemic of 1968, killing a million people around the world. The strain, H3N2, has circulated since and often sparks severe epidemics that are more likely to cause deaths and hospitalizations than other strains, especially among the elderly and very young.

"The 2024-25 influenza season, largely due to influenza A H1N1 and H3N2 viruses, was associated with high severity across all age groups, including an exceptionally high number of pediatric deaths. Unfortunately, we are seeing the circulation of a new variant of H3N2 virus for which our vaccines may be somewhat less effective,” said Dr. Hayden, part of UVA’s Division of Infectious Diseases and International Health. “However, available vaccines will reduce the risk of serious illness and potentially the spread of this virus.”   

That last part is key, he says. While the vaccines not be a perfect match this year, they are still the best way to protect yourself and reduce your chances of serious illness. “Getting vaccinated as soon as possible remains the single most important action people can do to protect themselves and their families,” Dr. Hayden said.  

In terms of prevention, Dr. Hayden also urges common-sense precautions such as keeping your distance from sick people by avoiding crowds, wearing a mask when that is unavoidable, and handwashing.

In addition to vaccination, seniors and other people at risk also should consider taking flu antivirals for prevention if they are exposed to someone with influenza where they live, Dr. Hayden says. If illness develops, prompt antiviral treatment can reduce the duration of the illness and the risk of complications.