New flu variant this season causing numbers not seen in a quarter-century

BETHLEHEM, Pa. — Imagine you’ve decided to protect your home by installing bolt locks on your front door.

And then you learn the intruder sneaked in the back door.

That’s akin to what has happened during the manufacturing of vaccines for the current flu season.

Well after pharmaceutical companies created their annual flu vaccines in anticipation of the peak months of the virus, a new variant of the virus — Subclade K — emerged.

And it's driving an uptick in cases across the United States not seen in a quarter-century.

A variant of the H3N2 family of viruses, Subclade K also is expected to increase flu symptoms and prolong the flu season.

“Subclade K is a subtype that reproduces and mutates,” said Dr. Alex Navarro Benjamin, chief infection control and prevention officer, infectious diseases, at Lehigh Valley Health Network.

“It’s a mutation variety of influenza A. This happens year to year.

"They noticed this variant in the Southern Hemisphere last fall when they were going through their flu season and saw increased cases.

“And by the time they found out about this variant, we [in the United States] had already made our vaccines for the season.”

Courtesy

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Lehigh Valley Health Network

'Our hospitals are being overwhelmed'

A subclade is a smaller, more specific subgroup in biology, including viral strains.

Flu continues to bring misery across the United States, with all but four states showing high or very high levels of activity as Subclade K continues to spread.

The United States is at its highest level of respiratory illness since at least the 1997-98 flu season, according to data published Monday by the U.S. Centers for Disease Control and Prevention.

An early paper published by the University of Pennsylvania from lab data showed that people who have the Subclade K infection and who got this year’s flu shots have a 30-40% protection, Benjamin said.

“But this is test-tube data,” he cautioned. “We don’t know [the level of protection] outside of that. Whether this new variant will be taxing on health systems is hard to say."

Benjamin said the numbers at LVHN facilities "are steadily picking up from our lab data."

"Our hospitals are being overwhelmed — not like in COVID, but our beds are full," he said. "But that’s not a surprise; this is flu season.

“The question is, how long will this last, will it stay at its peak and stay at a high number?”

Local hospitals report increases

Flu activity in the Eastern Pennsylvania region has reached high or very high levels immediately following the winter holidays, federal and state data shows.

Local hospitals and health systems are reporting an increase in visits to outpatient offices and emergency departments among children and adults with fevers, coughs, breathing issues and, in some cases, vomiting and other gastrointestinal symptoms.

During the week of Thanksgiving, flu activity in Pennsylvania, New Jersey and Delaware ranged from minimal to moderate.

But infection rates have risen rapidly and sharply, according to the Centers for Disease Control.

More than 14,300 positive flu tests were reported to the Pennsylvania Health Department in the week ending Jan. 3.

That’s compared with 1,690 total cases reported during the week ending Nov. 29.

Whether one has a typical case of the flu or Subclade K, the protocol remains much the same — bed rest and drinking plenty of fluids, Benjamin said.

With one caveat.

“Most importantly from a management standpoint, you may want to talk to your doctor about taking Tamaflu or Tamivir,” Benjamin said.

That's the antiviral prescription medications that slow the spread of the virus and reduce the impact of symptoms.

“We know that those are most effective when taken during the first 48 hours of any flu symptoms,” he said.