Estimating the undetected burden of influenza hospitalizations in children.

During the 2004-2005 influenza season two independent influenza surveillance systems operated simultaneously in three United States counties. The New Vaccine Surveillance Network (NVSN) prospectively enrolled children hospitalized for respiratory symptoms/fever and tested them using culture and RT-PCR. The Emerging Infections Program (EIP) and a similar clinical-laboratory surveillance system identified hospitalized children who had positive influenza tests obtained as part of their usual medical care. Using data from these systems, we applied capture-recapture analyses to estimate the burden of influenza related-hospitalizations in children aged<5 years. During the 2004-2005 influenza season the influenza-related hospitalization rate estimated by capture-recapture analysis was 8.6/10,000 children aged<5 years. When compared to this estimate, the sensitivity of the prospective surveillance system was 69% and the sensitivity of the clinical-laboratory based system was 39%. In the face of limited resources and an increasing need for influenza surveillance, capture-recapture analysis provides better estimates than either system alone.

Challenges in the development, licensure, and use of combination vaccines.

Before substantial public health benefits associated with use of combination vaccines can be realized, a variety of challenges must be addressed. In February 2000, the National Vaccine Program Office convened the International Symposium on Combination Vaccines to explore solutions for barriers to development, licensure, and use of safe and effective combination vaccines. The symposium focused on the following questions: (1) What immunologic standards should be used to evaluate new combination vaccines? (2) How should correlates of protection be developed, and how should the data they provide be interpreted? (3) What sample size is adequate for prelicensure safety trials of combination vaccines? (4) Should standards for evaluation of combination vaccines containing licensed components be different from standards for evaluation of combinations containing unlicensed components? (5) How can the "great expectations" of postlicensure surveillance be realized? Available data relevant to these issues were presented, providing a foundation for furthering the science of combination vaccines.

Adult immunization programs in nontraditional settings: quality standards and guidance for program evaluation.

This report provides a summary of the National Vaccine Advisory Committee's (NVAC) workshop on adult immunization programs in nontraditional settings, quality standards for such programs, and guidance for program evaluation. Throughout the United States, an increasing number of adults are receiving vaccine in nontraditional settings (e.g., pharmacies and churches). Immunization programs in nontraditional settings are often more accessible and convenient than a health-care provider's office or a public health clinic, especially for medically underserved adults (e.g., economically disadvantaged, inner city, and minority populations). Medically underserved adults might be at particular risk for undervaccination because they are often without a medical home (i.e., a regular point of contact where their health-care needs are met). Immunization programs in nontraditional settings might enhance the capacity of the health-care system to effectively deliver vaccine to adults by increasing the number and types of sites where adults can receive vaccine. NVAC has recognized that strategies need to be developed to make vaccines available to all adults and that the number of immunization programs in nontraditional settings is increasing. Therefore, the Committee issues the following report, including quality standards and guidance for program evaluation.