Flu activity is now considered "high" in 34 states, according to the U.S. Centers for Disease Control and Prevention. At least 2,900 people have died and the flu hasn't been this widespread this early in the season in more than a decade.
At Riley Hospital for Children in Indianapolis,begins at the front door. The hospital has created influenza checkpoints, where security keeps a list of approved visitors, mostly parents.
"Even when they visit and they're on the list, they're screened for illness, so fever, cough, runny nose, body aches," said Dr. Elaine Cox, an infectious disease specialist.
The goal is to create a ring of protection around vulnerable kids. That's especially important to DeAnthony Knighten and his 10-year-old son, DeAnthony Junior, who is on kidney dialysis.
"His immune system is a lot weaker with his condition so making sure that we are all vaccinated is very important to make sure he stays at 100% with his health," Knighten said.
The CDC reported Friday there have been more than 55,000 hospitalizations this flu season. Usually, the predominant strain is influenza A, but this year so far, it's been influenza B. What comes next is anyone's guess.
"We'll have to wait and see what happens in the coming weeks. Even if we are at peak we still have half of the flu season to go and there may be other other viruses circulating after the influenza B's that are here right now," said Lynette Brammer with the CDC.
It's still too early to say how effective this year's flu vaccine will end up being. But with the flu season occurring earlier than usual and accelerating, the CDC is reminding people it's not too late to get immunized.