CHICAGO (CBS) — The leaves are starting to change and there is definitely a chill in the air, so you can be sure that flu season is just around the corner.

The Chicago Department of Public Health is offering flu shots across the city during its annual vaccination drive, and officials are urging everyone to take advantage.

“The flu shot is a very safe and effective vaccine that we’ve had for many years, and so we know it’s a good thing, and it’s the best thing to prevent the flu,” said Dr. Julie Morita, medical director at the department.

You may think of the dead of winter more than early fall when you think of the flu. But Morita says now is the time to get the flu shot, not the middle of flu season.

“I think every year, we never know when the flu season will start. Most of the time, it starts in February, or peaks in February or later. But getting vaccinated now, before we start seeing the flu, is a great time to get vaccinated,” Morita said.

Even if you have never gotten a flu shot, Morita says now is the time to start.

“There’s many reasons to get the vaccination,” she said. “Currently, everybody, 6 months and older, should get a flu vaccine, because people miss work. Many people can be hospitalized and get seriously ill because of the flu. So pregnant women, very young children, the elderly, people with chronic diseases like diabetes or heart disease – those people can end up in the hospital with influenza infections.”

But regardless of whether you’re in a high-risk group, Morita says you should get the vaccine. Influenza is a highly communicable disease, and can be spread to people for whom it could be serious, she says.

The free flu vaccinations are being offered at Department of Public Health sites all across Chicago, through Dec. 8. For more information, go to cityofchicago.org/flu.