CHICAGO (CBS) — The Centers for Disease Control and Prevention is issuing a reminder that if you haven’t already gotten a flu shot this season, now is the time to do it.

As WBBM Newsradio’s Regine Schlesinger, CDC senior adviser Dr. Raymond Strikas says flu season does not usually peak until January or February, but so far, this is a mild one.

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LISTEN: WBBM Newsradio’s Regine Schlesinger reports

“Not a lot of flu activity so far, but there has been some H1N1 reported in the U.S., which is why it’s included in this year’s vaccine,” Strikas said.

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He says large holiday gatherings prove perfect breeding grounds for the influenza virus, so this is a good time to be immunized.

And the flu doesn’t necessarily mean just a week of sore throats, fever and misery. Complications are possible, and the very old, the very young, and the chronically ill are the most vulnerable, Strikas said.

“All these folks, because of their age or health status; immune system status, have an increased risk of complication – either pneumonia, hospitalization with the worsening of their chronic condition, or rarely, even death,” he said.

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Seasonal flu is blamed for anywhere from 3,000 to 49,000 deaths each year, according to Strikas.