The state Department of Health has launched this year’s Protect Hawaii’s Keiki: Stop Flu at School program.

It offers free flu vaccines to 333 public, private and charter schools this fall. Now in its fourth year, the voluntary statewide program is designed to prevent the spread of flu among school children and their families.

Parent and guardian information packets and consent forms are being sent home with children attending participating schools.

Health officials said today that consent forms must be completed and returned to the child’s school by Sept. 9.

Last year, the program immunized more than 70,000 children, a 16 percent increase since the program began. Nearly 10,000 faculty and staff also took advantage of the free program.