Officials at the University of Tennessee Medical Center say they're seeing an early increase in influenza reports.
UT Medical Center infection prevention manager Jennifer Radtke tells the Knoxville News Sentinel that although it's too early to determine if this winter will be a bad season for the flu, the hospital has seen growth in the number of reported cases this month.
As of Wednesday, UT Medical Center had seen 64 people in December who tested positive for the flu.
In December 2016, 25 people tested positive at the hospital. Radtke says the increased cases this season are partly caused by a mismatch between the vaccine and the flu strain circulating.
The Centers for Disease Control and Prevention has seen the vaccine's effectiveness between 10 and 33 percent. Flu activity in the U.S. usually peaks around February.