Last year's drastically low number of flu cases may play a part.

Though the US is about to hit the two-year mark of dealing with the COVID-19 pandemic, it's not the only infectious disease that should be on people's radars right now—the upcoming flu season (2021-2022), could be more severe than we've seen in the recent past.

That information comes from Rochelle Walensky, MD, MPH, director of the Centers for Disease Control and Prevention (CDC). Dr. Walensky issued that warning Wednesday during a press briefing by the White House COVID-19 Response Team and other public health officials.

CDC Warns of Severe Flu season
Credit: Getty Images

"Last year there were very few flu cases, largely because of masking and physical distancing and other prevention measures put in place for the COVID-19 pandemic" Dr. Walensky said. "With modest flu virus activity since March of 2020, CDC's flu experts are concerned that reduced population-level immunity to the seasonal flu could place us at risk for a potentially severe flu season this year."

CDC data shows those drastically low numbers—between October 3, 2020 and July 24, 2021, the CDC saw only 2,136 positive flu tests out of 1.3 million specimens tested by clinical laboratories, according to official data provided to JAMA. Only 736 deaths were recorded as influenza. For reference, the 2019–2020 flu season saw an estimated 35 million flu-related illnesses and 20,000 flu-related deaths, the CDC says.

To help stave off a more severe flu season—and to prevent more hospitals from being overwhelmed—Dr. Walensky went on to urge people to not only get their annual flu shot this year, but also get vaccinated against COVID-19 if they haven't already. She noted that, though hospitalization rates for COVID-19 are on the decline right now, some hospitals are still at full capacity, which could lead to issues with a severe flu season. Each year in the US, influenza "results in 140,000–710,000 hospitalizations—another toll we need to work hard to avoid," said Dr. Walensky.

COVID-19 fatigue may also be a contributing factor to a potentially more severe flu season, Richard Watkins, MD, an infectious disease physician and professor of internal medicine at the Northeast Ohio Medical University, tells Health. With more people being out and about—despite concerns of COVID—"there is a higher risk of getting the flu," says Dr. Watkins.

It's important to note though that a severe flu season is only a possibility—nothing is known for certain as of yet. Amesh A. Adalja points to the flu season those in the southern hemisphere just experienced as potential clues to what ours will look like (they have their flu season before ours—our summer is their winter—and so it's typically a good predictor of how our flu season will turn out). "The southern hemisphere had another light flu season, which might portend a light flu season for us," says Dr. Adalja.

Overall, the best way to protect yourself and others from a possibly severe flu season, is to continue the preventative measures that you've used in the past against the flu, COVID-19, and other viral illnesses. "Mask-wearing, social distancing, and hand washing will also help lower the risk," says Dr. Watkins.

And because immunizations—both the COVID-19 vaccine and the flu vaccine—are essential to protecting yourself from the viruses, Dr. Walensky also stressed in the news conference that it's totally safe to get your annual flu vaccine with your COVID-19 shot.

"Just like with COVID-19, we need as many people as possible to be vaccinated for influenza, so that we can provide protection for those who are at most risk," Dr. Walensky said. Again, per Dr. Walensky, that includes: "Adults who are over 65, those of any age who have chronic health conditions such as asthma, heart disease or diabetes, and children, especially under five who are at risk of severe complications from the flu."

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