The U.S. government’s Healthy People 2010 initiative set a goal of vaccinating 90 percent of U.S. health care workers for hepatitis B. This goal hasn’t been met, and that’s largely due to a lack of childhood vaccination, according to a Centers for Disease Control and Prevention (CDC) study reported by ThirdAge.

For the study, CDC researchers examined immunization records from 4,075 health care students enrolled at a university in the southeastern United States between 2000 and 2010. The researchers found that only 59.3 percent of the students had documentation for hepatitis B vaccination—and that a majority of those with documented vaccination were vaccinated within a few years of graduation, rather than in childhood.

The CDC’s Advisory Committee for Immunization Practices recommends vaccinating all newborns for hepatitis B, as well as unvaccinated adolescents and at-risk adults.