Influenza and Pneumococcal Vaccination: How Far We Have Come and How to Go Farther

Abstract

The recent outbreak of avian influenza in Asia is a timely reminder of the ever present possibility of a human influenza pandemic in the near future.1 Work continues to develop vaccines effective against emergent influenza strains, but another component of effective prevention and infection control programs is the ability to administer vaccine in a timely and efficient manner. Even in the absence of a pandemic, influenza-associated respiratory and circulatory illness results in more than 200,000 hospitalizations and 36,000 deaths each year in the United States, according to recent estimates.2,3 These numbers suggest that the routine administration of influenza vaccine to targeted populations remains a major challenge. The efficacy of influenza and pneumococcal vaccines in preventing illness is well established,4,5 and during the past decade substantial progress has been made in increasing influenza and pneumococcal vaccination coverage in targeted populations. Estimates of influenza vaccination levels among individuals 65 years and older based on the National Health Interview Survey (NHIS) showed an increase from 33% in 1989 to 66% in the 2001–2002 season.4,6 NHIS estimates for pneumococcal vaccine coverage in this population also increased (from 15% in 1989 to 54% in 2001).6,7 However, influenza vaccination rates in all other targeted adult populations remained well below 50% in the 2001–2002 season, including healthcare workers (38%) and adults 18 to 49 years old with high-risk conditions (23%).4 Influenza vaccination rates among children at increased risk for influenza complications have also been low.4 This year, the Advisory Committee on Immunization Practices (ACIP) extended use of influenza vaccine by recommending vaccination for healthy children 6 to 23 months old and close contacts of children 0 to 23 months old.4 These figures suggest that despite some progress, targeted populations, including many workers and patients of healthcare institutions, still remain vulnerable. In this issue of Infection Control and Hospital Epidemiology, several articles address the challenges we face in further increasing vaccination levels among targeted populations.8-12 The study by Coyle and Currie is a welcome addition to the literature about interventions to increase pneumococcal vaccination rates among hospitalized patients.8 This study compared a standing orders protocol with computerized physician reminders and with routine practice in a prospective trial. The study found a clear superiority of standing orders over physician reminders, a finding consistent with previous studies13 and supportive of the ACIP recommendation for healthcare institutions to implement standing orders programs to increase pneumococcal and influenza vaccine coverage of high-risk individuals.4,5 Two studies examine employee influenza vaccination policies at healthcare institutions.9,10 In a large survey of healthcare institutions in North Carolina, Goldstein et al. found that only 38% reported having formal written policies regarding employee influenza vaccination.9 The lowest rates were found in assisted living facilities and dialysis centers. The authors also noted that barriers to increasing levels of influenza vaccination may differ depending on the type of institution, further emphasizing the need to adapt vaccination interventions to the specific needs of an individual institution. The article by Bryant et al. describes a survey of influenza vaccination policies among several pediatric hospitals.10 The median employee vaccination rate reported by infection control practitioners was 43% in this voluntary survey. A point-prevalence survey of employ-