By Lynne Adkins

PHILADELPHIA (CBS) — Commercials encouraging you to get a flu shot appear to be everywhere this time of the year. A local doctor encourages you to get a flu shot, but says you can wait a little.

Flu season generally begins in October and runs through late March, of course that’s just a guideline, and the illness can strike earlier or later in the year.

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Dr. Bindu Kumar, Associate Medical Director for Occupational Employee Health at Main Line Health System says the Centers for Disease Control recommends you get a flu shot in October because the vaccine protection only lasts so long.

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“It tends to go down over time, we know that folks who have robust immune systems will have good protection for the duration of the flu season, but if that flu season tends to run into the spring it tends to not be as effective down the road,” she says.

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She says anyone 6-months and older should be vaccinated.