H1N1

Matt Rourke / AP Photo

Local health officials are urging people of all ages to get vaccinated against the flu, which has already claimed four lives in King County alone this season.

In addition to the deaths, the number of positive tests has doubled since mid-December, according to Dr. Jeff Duchin with Public Health – Seattle & King County. And this year's most prevalent strain, the H1N1 virus, is one that hits younger people especially hard.