NEW YORK (Reuters Health) – Adolescent immunization rates are far from optimal, and many opportunities to make sure that teenagers receive recommended immunizations are being missed, according to a new study.

To better understand why immunization rates are low among adolescents, Dr. Grace M. Lee at Harvard Pilgrim Health Care in Boston and associates reviewed records of patients enrolled in their large group practice in Boston.

Included were nearly 24,000 adolescents who had approximately 348,000 outpatient visits between 1997 and 2004, of which 77% were for non-preventive care, 18% were for preventive care, and 5% were vaccine-only visits.

Among 13-year-olds born between 1989 and 1991, 84% were up to date for tetanus-diphtheria, 74% for hepatitis B, and 67% for measles-mumps-rubella immunizations.

Their hepatitis B and MMR coverage rates were significantly lower than the US national average, as well as rates reported by the Massachusetts Department of Public Health, which, according to the authors, “highlights the problem of record scattering in the adolescent population, because this group may be receiving vaccines from different types of providers over time.”

These findings “underscore the need for providers to assess accurately the up-to-date status of all adolescents, especially for vaccines that are also given in early childhood.”

One way to improve adolescent immunization rates, Dr. Lee’s group says, is to encourage annual preventive care services among these patients and their parents.

“Second,” they add, health care providers “may need to refocus their approach toward immunizing adolescents when the opportunity arises, such as during nonpreventive visits.”

Pediatrics 2008;122:711-717.