The state of North Carolina has already confirmed two flu deaths in adults. Officials say only one of them was already at higher risk due to advanced age and preexisting medical conditions.
Many of the cases are of the H3 strain, which is particularly dangerous for the elderly.
Experts say the mild weather shouldn't fool us.
"Although we have had relatively mild weather if you look at the data in Chicago in Illinois and the United States we have actually gotten more flu activity in the community now than we normally see now the good news is the flu vaccines that we have look like they are a good match for what is circulating so there is every reason to expect the vaccine we have is going to work just fine," Dr. Kenneth Alexander, University of Chicago Medical Center, said.
Health officials stress that prevention -- from getting the flu shot to washing our hands, and to staying home when we are sick -- is key.