Influenza vaccination coverage among persons aged 50-64 years enrolled in commercial managed health-care plans--United States, 2003-04 and 2004-05 influenza seasons.

To combat an unexpected shortage of influenza vaccine in the fall of 2004, CDC issued guidance to direct available vaccine supplies to persons in designated priority groups (e.g., persons aged >/=65 years, persons with certain health conditions, health-care workers, and close contacts of persons at high risk for complications from influenza). Analyses of influenza vaccination coverage for the 2004-05 influenza season indicated that coverage levels for adults in priority groups nearly reached the levels of previous years, whereas coverage levels among adults not in priority groups were approximately half the levels of the 2003-04 season. These findings suggested that national public health actions to direct available vaccine supply to persons at high risk for complications from influenza during the supply disruption were successful. To assess influenza vaccination coverage among persons aged 50-64 years for the 2004-05 influenza season relative to the 2003-04 season and to estimate the effect of shortages on selected subgroups, the National Committee for Quality Assurance (NCQA) analyzed data from a survey of persons enrolled in commercial managed care health plans. This report summarizes the findings of that analysis, which indicated that, although vaccination coverage declined substantially from 2003-04 to 2004-05 among all subgroups in this age range, respondents who were older or who reported poorer health status exhibited smaller relative declines in vaccination coverage between the two seasons.