Louisville’s heath department and Jefferson County Public Schools are embarking on a campaign to immunize thousands of studentsagainst the flu. The immunization campaign was launched two years ago in response to the H1N1 outbreak. This year’s free doses of combined H1N1 and seasonal flu vaccine are funded by various federal programs. Health department spokesman Dave Langdon says the first shots will be administered this week at six schools. "Over the course of the next eight or nine weeks, through December 8, we’ll be out for one day at every Jefferson County public school," Langdon said. Students must have written parental permission to get a shot. Officials expect to vaccinate about 20,000 or 20 percent of JCPS students.