June 6, 2005

Study Supports Whooping Cough Booster Shot for Adolescents

BOSTON - Despite childhood vaccination rates at all-time highs, pertussis (whooping cough) has re-emerged over the past two decades, especially among adolescents, adults, and young infants. Because of this resurgence, federal health policymakers are considering a national booster vaccination program. An analysis by Harvard Medical School researchers in the June issue of Pediatrics offers support for the adolescent booster, concluding that one-time vaccination at 11 years of age may potentially be cost-effective.

The Advisory Committee on Immunization Practices, which advises the Centers for Disease Control and Prevention, meets on June 29-30 and will consider pertussis boosters. Combined acellular pertussis vaccines for adolescents and adults are available in Canada, Australia, and Germany.

Led by Grace Lee, MD, MPH, Harvard Medical School Instructor of Ambulatory Care and Prevention at the Department of Ambulatory Care and Prevention's Center for Child Health Care Studies, the researchers compared six vaccination strategies, ranging from no vaccination after age 6 to adolescent and adult vaccination with 10-year boosters. The computer simulation model used incorporated existing data on pertussis incidence, disease outcomes, vaccine efficacy, vaccine costs, and side effects. (The Department of Ambulatory Care and Prevention is a unique research and teaching collaboration between Harvard Pilgrim Health Care and Harvard Medical School.)

The analysis concluded that one-time adolescent vaccination "would result in significant net health benefits and may be reasonably cost-effective," preventing 36 percent of projected pertussis cases at a cost of $20,000 per quality-adjusted life year saved or $1,100 per case prevented. These estimates -- less favorable than those for Haemophilius influenza B (Hib) or measles vaccination, but similar to those for pneumococcal vaccination -- were highly sensitive to assumptions about disease incidence, vaccine efficacy, side effects, and vaccine costs, the authors write.

"In the past, vaccination programs were cost-saving and life-saving," says Lee, who is also an infectious disease specialist at Children's Hospital Boston. "However, newer vaccines are now focused on reducing morbidity, rather than mortality, and we need to carefully weigh the risks and benefits of vaccination. By balancing the costs of a vaccination program and the potential impact of alternative vaccine policies on reducing disease morbidity and improving quality of life, we can optimize decision making regarding vaccine use in the US."

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