Why the flu shot is less efficient - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

Why the flu shot is less efficient

Posted: Updated:

SPOKANE, WA - 'Get your flu shot;' that's what doctors are still telling people - especially since this year the flu is so widespread and deadly.

So why doesn't the flu shot work? Can it make you sick? And why should you get one?

Dr. Andrew Dill with MultiCare Rockwood Clinic says he's seen plenty of people for the flu this season.

 "The flu window is from October to really April," said Dr. Dill.

He says it's never too late to get a flu shot.

"Anytime is fine. The immunity takes between 2 to 4 weeks to fully achieve effect."

But why does it seem like the flu shot isn't working this year?

"We've seen two numbers used, which is a 10 percent and 32 percent efficacy this year compared to the normal 60 to 70 percent of the flu vaccination," Dr. Dill said. This is not be to unexpected because normal years they are required to determine what flu strains will be out. This year's flu strains were not the expected strains so that's the reason for the reduction in the efficacy."

As for getting a bad reaction to the flu shot?

"It's pretty rare. Less than 5 percent. When people say that they've received a flu shot and gotten the flu from it, that's a myth."