Flu Season: What to Know This Year
Editor's Note: This story was updated Jan. 8, 2018.
The flu is here and spreading nationwide – CDC officials says they saw a sharp increase in the past week. They are also seeing more activity this year than at the same time last year. In fact, the CDC says, this year's flu season is similar to what was seen at the peak of the 2014-2015 season, which was the worst in recent years.
Flu is a contagious disease, and it can cause mild to severe symptoms along with life-threatening complications, even in young, healthy children and adults.
Since 2010, the flu has killed from 12,000 to 56,000 people annually in the U.S. and affected about 9 million to 35 million annually.
Here is what else to know about flu.
What's the latest news about this year's flu season?
Flu activity is widespread in 46 states, and regional or local activity has been reported in Maine, New Hampshire, New Jersey, Hawaii and Washington, D.C. Health officials in California and Illinois, among others, are reporting that this year's flu season is already out-pacing last year's.
In Illinois, officials say, current flu levels are higher than any season since 2009-10, according to the Chicago Tribune.
Ohio health officials report more than 900 flu-related hospitalizations and say this year's flu season has seen more cases by this point than a year ago, according to media reports.
How effective is this year's flu vaccine?
As more states report widespread flu, public health officials are monitoring how well this year’s vaccine matches the strains they are seeing most often. Despite some early reports that the vaccine wasn’t a good match, a recent study suggests it may work better than expected.
In Australia, the vaccine was only 10% effective this season, and their most common virus was H3N2. Although H3N2 is also the most common virus circulating in the U.S., it’s not the same strain as the one in Australia, according to the study published in F1000 Research.