Flu season 2022 started a month early, severity is highest in 13 years

Not since the 2009 H1N1 swine flu pandemic has there been such a high burden of flu, a metric the CDC uses to estimate a season’s severity based on laboratory-confirmed cases, doctor visits, hospitalizations and deaths.

“It’s unusual, but we’re coming out of an unusual covid pandemic that has really affected influenza and other respiratory viruses that are circulating,” said Lynnette Brammer, an epidemiologist who heads the CDC’s domestic influenza surveillance team.

Activity is high in the U.S. south and southeast, and is starting to move up the Atlantic coast.

The CDC uses a variety of measures to track the flu, including estimating the percentage of doctor visits for flu-like illness. But given the similar symptoms that could include people seeking care for covid-19 or RSV, another respiratory virus with similar symptoms, the laboratory data leaves no doubt.

“The data are ominous,” said William Schaffner, medical director for the nonprofit National Foundation for Infectious Diseases and a professor of infectious diseases at the Vanderbilt University School of Medicine. “Not only is flu early, it also looks very severe. This is not just a preview of coming attractions. We’re already starting to see this movie. I would call it a scary movie.”

Adding to his concern, he said, is that influenza vaccination is lagging behind where it usually is at this point in the season. About 128 million doses of flu vaccine have been distributed so far, compared with 139 million at this point last year and 154 million the year before, according to the CDC.

“That makes me doubly worried,” Schaffner said. The high burden of the flu “certainly looks like the start of what could be the worst flu season in 13 years.”

RSV, other viruses making it hard to find a bed in children’s hospitals

The number of flu cases this season is already one-eighth of last season’s total estimate of 8 to 13 million cases.

The latest flu data comes as the nation’s strained public health system is grappling with multiple virus threats. Coronavirus cases are expected to increase as the country heads into colder weather and more people gather indoors. New covid-19 subvariants with greater ability to dodge immune defenses now account for 27 percent of cases, up from 17 percent a week ago. Children’s hospitals are filling up with a record number of kids infected with RSV.

The flu vaccine’s effectiveness in preventing a doctor visit,…