Illinois is among 30 states reporting high flu activity in a season where the virus is striking earlier than usual and the main flu strain is one that tends to make people sicker.
Illinois Department of Public Health spokeswoman Melaney Arnold said Friday that 476 people have been admitted to hospital intensive care units with the flu this season and 50 have died.
Public health officials continue to encourage people to get vaccinated.
One bright spot: Chicago's flu hospitalizations continued a two-week decline.
Last week there were nine patients in hospital intensive care units with the flu, a decrease from 31 the previous week.
Dr. Julie Morita of the Chicago Department of Public Health says the demand for vaccine remains high, but it's not overwhelming. She says supplies are good.