Taking the long view of new goals for immunization

During the past 50 or 60 years, physicians and society at large have become accustomed to the notion that immunizations prevent disease during childhood. Of course, paralytic polio and tetanus did affect adults during the pre-vaccine era, but vaccines have, in general, been administered during infancy and childhood-the expectation being that children would escape infection and disease during a period of physiologic vulnerability. Even the hepatitis B vaccine, which offers protection through a period of risky behavior in adolescence and young adulthood, is viewed by pediatricians primarily as a means of protecting newborns from maternal transmission.

With the recent licensing of a conjugated, quadrivalent meningococcal vaccine (MCV4) and likely approval of other "childhood" vaccines to prevent disease during adolescence and adulthood, however, the national immunization program ventures onto new ground: namely, approving expensive vaccines that have the potential to extend protection throughout adulthood but whose benefit cannot be measured easily. The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention recommends that MCV4 be given to all children at 11 or 12 years of age and to college freshmen and other high-risk people. This recommendation is a compromise of cost-effectiveness, balancing the lowest cost for every infection prevented and the most deaths prevented. (Infants and toddlers are, in fact, the age group at highest risk of infection and death from Neisseria meningiditis meningitis, yet about 50% of infections among preschoolers are caused by strains of serogroup B, which MCV4 does not prevent.)

Even this more cost-effective approach is going to be expensive. The Meningococcal Workgroup of the ACIP estimates that, if 71% of 11- and 12-year-old children are vaccinated, it will cost $61,000 to prevent one case of invasive meningococcal disease and $464,000 to prevent one death. The rice of MCV4 has not been established, but the Workgroup estimates that, if the price of one dose of the vaccine is set at $75, the program will cost $121,000 for every life-year saved. Compare that to the current estimate of $80,000 for every life-year saved by the conjugated pneumococcal vaccine (PCV7) and the estimate of more than $100,000 for every life-year saved by annual mammography for women between 40 and 50 years of age.

It's exciting to contemplate the additional opportunities these vaccines might provide to improve the health of young people, even after they are no longer "pediatric patients." The monetary cost will be high, but the possibility of a very long-term impact is even higher.

Julia A. McMillan, MD, editor-in-chief of Contemporary Pediatrics, is professor of pediatrics, vice chair for pediatric education, and director of the pediatric residency training program, Johns Hopkins University School of Medicine, Baltimore.