Public education. The Department of Health developed a coordinated national campaign to promote immunization. This effort relies on funds budgeted specifically for immunization education. Professional advertising agencies developed the television spots used in the campaign. Because the television districts and health districts cover very similar regions, it has been possible to target the immunization message to those districts with lower immunization rates. Follow-up research has been done to test the impact of the advertising. An intensive effort made at the time that the Hib (Haemophilus influenzae type b) vaccine was introduced proved to be very successful.