An early fall spike in influenza cases has pushed U.S. hospitalization rates for the illness to the highest in a decade for this time of year, U.S. health officials said on Friday, noting that vaccination rates are down.

The rising flu cases come alongside pressure on hospitals from respiratory syncytial virus (RSV) and COVID cases, officials said, urging people to get vaccinated and offering to assist states that may need additional support.

"There's no doubt we will face some challenges this winter," U.S. Department of Health and Human Services' Assistant Secretary for Preparedness and Response Dawn O’Connell told reporters, adding that the flu season so far does not seem more severe but has arrived earlier than is typical.

There have been 5 million fewer doses of influenza vaccine administered to U.S. adults so far this year compared to this time last year, officials said. Flu vaccine uptake is about the same for children this year but overall is down 6% compared to before the COVID pandemic began in 2020.

About 5% fewer pregnant people have received flu shots so far this season, which officials say is especially worrisome because the vaccine protects both the expecting mother and her baby, officials added.

U.S. flu shots are made by Sanofi SA, GSK and Seqirus, a unit of CSL Ltd.

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