We're heading into the holiday season, but it's also the sickest time of the year. December through February is the peak flu season in the United States, and experts are forecasting a possible "flu-pocalypse."
According to a new report from the Centers for Disease Control, the number of flu cases has doubled this year, compared to last.
This year's vaccine is only 10% effective. They're usually 42% effective.
Another reason for concern is that Australia had an especially severe flu season this year, and the U.S. generally follows what happens in the Southern Hemisphere.
The flu strain circulating in Australia was known as H3N2. That kind of virus tends to make people sicker than other strains, especially the elderly.
Health officials still suggest getting the flu shot is the way to go.
Tammara Scroggins, from the Department of Health & Human Services, explains, "Always the number one recommendation is to receive the vaccination and influenza vaccination while the reports are saying the vaccine is about 10% effective anything is good versus nothing."
The CDC says it's never too late to get the flu vaccine this winter, but the sooner, the better.
They also stress that flu seasons are notoriously difficult to predict and just because Australia's is particularly bad, doesn't mean America's will be. Americans tend to be more highly vaccinated than Australians. And a slightly different flu strain could end up dominating this country altogether.