(CNN) – The CDC said the current influenza virus has mutated, making this year’s vaccination less effective.
If you got a flu shot recently, don’t be surprised if you still get sick.
In an advisory to doctors, the Centers for Disease Control and Prevention said influenza virus samples taken from Oct. 1 through Nov. 22 showed just under half, or 48 percent, matched the current influenza strains in this year’s vaccine.
Just over half, 52 percent, of the samples were different, indicating a mutation or drift of the strain.
The CDC still recommends getting vaccinated, since it can still decrease the severity of the illness.
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