This year's flu vaccine was less effective than officials previously thought, particularly for the elderly, said officials with the Centers for Disease Control and Prevention.
The CDC says the vaccine only helped nine percent of people aged 65 and older.
For those under 65, the vaccine was about 56 percent effective.
"One possible explanation for this is that some older people did not mount an effective immune response to the H3N2 component of this season's vaccine," the report said. "However, it's not possible to say that for sure."
But the CDC says even with the disappointing numbers, it's still worth it for everyone to get a flu shot.
