The Division of Public Health says about one in four students received the vaccine at eight Delaware schools Monday. Thirty-eight percent of elementary school students returned parental consent forms for the vaccine.
State Department of Health and Social Services spokesman Carl Kanefsky says officials expect more middle and high school students to participate.
Delaware officials didn't have a conclusive reason why more children didn't receive the vaccinations. Kanefsky says some may be getting vaccines from family doctors.
Division of Public Health spokeswoman Heidi Truschel-Light says some parents choose not to vaccinate their children.
Information from: The (Wilmington, Del.) News Journal, http://www.delawareonline.com