The Centers for Disease Control and Prevention says three more children died of flu-related causes last week, bringing the total number to 22 this season.
Flu activity is expected to remain elevated for several more weeks.
Flu deaths in California: Illness killed 42 people since September 2018
Schools in several states, including California, have had to cancel classes because of an outbreak of the flu.
Federal health officials say up to 11.4 million people have been sick with the flu so far this season.
MORE: The extra benefits of yearly flu shots