CDC reported over 34,000 positive flu cases in the week ending Nov. 26—the highest number of positive flu cases ever recorded in a given week—and hospitalizations continue to be high across the United States. The flu, combined with Covid-19 and respiratory syncytial virus (RSV), has experts saying that it is shaping up to be "a perfect storm for a terrible holiday season."

Flu cases continue to be high across the US

According to CDC, 44 U.S. states and jurisdictions reported "high" or "very high" influenza-like illness (ILI) activity, and four reported "moderate" activity, for the week ending Dec. 3. Two jurisdictions reported "low" ILI activity, and three reported "minimal" activity.

For the week ending Dec. 3, 25,906 patients were hospitalized with the flu—up from 19,593 patients the week before. In addition, the percentage of ILI outpatient provider visits was 7.2%, down slightly from 7.5% the week before but still higher than the baseline of 2.5%

The cumulative flu hospitalization rate, which is currently at 26 per 100,000 people, is the highest it has been for this time period since the 2010-2011 flu season. Over the past decade, the cumulative hospitalization rate for the same week of the year has typically been between 0.1 and 2.7 per 100,000.

So far this season, CDC estimates that there have been at least 13 million flu illnesses, 6.1 million flu medical visits, 120,000 flu hospitalizations, and 7,300 flu deaths.

There were seven pediatric deaths from flu reported the week ending Dec. 3—bring the total number of pediatric flu deaths this season to 21.

"The rise in cases and hospitalizations is especially worrisome as we move into the winter months, when more people are assembling indoors, with less ventilation, and as we approach the holiday season, where many are gathering with loved ones across multiple generations," said CDC Director Rochelle Walensky.

"This year's flu season's off to a rough start," said Sandra Fryhofer, board chair of the American Medical Association. "It started early, and with COVID and RSV also circulating, it's a perfect storm for a terrible holiday season."

Health officials reiterate calls for flu vaccination

With flu cases and hospitalizations continuing to rise, health officials are continuing to encourage people to get vaccinated, saying that this year's vaccines appear to be a "very good match" for the currently circulating flu strains.

"We look in real time as to how well we think the influenza match is to what's circulating. And right now, the good news is that it looks like it is a very good match," Walensky said.

So far, almost every flu sample tested by public health laboratories has been from the Influenza A viruses, but Influenza B viruses may still emerge after cases from Influenza A peak. "[J]ust because we haven't seen a lot of influenza B so far, it may be coming, if this is a typical influenza season," said Tim Uyeki from CDC.

According to Fryhofer, Americans should not let down their guard against the flu, even if they have already been infected and recovered once this season. She urged people to get vaccinated against the flu rather than risk another infection.

"We've forgotten how bad the flu can be," Fryhofer said. "But this year's season is a shout out that it can get really bad and it's here, so people need to get vaccinated."

Through mid-November, flu vaccination rates for children were around 40%, similar to last year's, but lower than rates from the 2020-21 and 2019-20 seasons. Vaccination rates among U.S. adults currently range from 18.9% to 35.6%, a drop from recent years when adult vaccination rates ranged from 45% to 50%.

"I know everyone’s tired of getting shots," Fryhofer said. "We all have booster fatigue. But understand. You could get really, really sick this year and ruin your holiday celebrations if you don't get vaccinated." (Landman, Vox, 12/6; Tin, CBS News, 12/5; Milton/Baumann, Bloomberg, 12/5; Heavey/Humer, Reuters, 12/6)