Flu cases across the country are on the rise, with 36 states now reporting widespread activity of the virus, according to the Centers for Disease Control.
And the end might not be in sight for several weeks, as flu season typically peaks in February.
Here are eight things to know about this year's flu season -- and how it compares to last season -- according to the CDC:
• Widespread flu activity was reported in 36 states during the week of Dec. 23, up from 23 the week before. At least nine deaths have been reported.
• 21 states, including Texas, Oklahoma and Louisiana, are classified as "high activity" areas for the flu.
• Nationwide, positive flu tests from clinical labs jumped from about 4,500 to about 6,500 the week before Christmas.
• 5 percent of outpatient visits were for flu-like illnesses during the week of Dec. 23, the highest this season and up from about 3.5 percent the week before. Last season's high peaked around five percent in February.
• 2,485 people have been hospitalized with flu-like illnesses since Oct. 1. Last season, 6,804 people were hospitalized from Oct. 1, 2016 to Feb. 4, 2017.
• Adults 65 and older have been hospitalized at the highest rate, the same as last season.
• In Texas, more than 14 percent of outpatient visits were for flu-like illnesses during the week of Dec. 23, the highest number since 2014.
• While some reports estimate that the flu vaccine is 10 percent effective this season, the CDC still recommends getting vaccinated. The vaccine was 39 percent effective last season.