Description of an influenza vaccination campaign and use of a randomized survey to determine participation rates

OBJECTIVES. To describe the procedures used during an influenza immunization program and the use of a randomized survey to quantify the vaccination rate among healthcare workers with and without patient contact. DESIGN. Influenza immunization vaccination program and a randomized survey. SETTING. Johns Hopkins University and Health System. METHODS. The 2008/2009 Johns Hopkins Influenza Immunization Program was administered to 40,000 employees, including 10,763 healthcare workers. A 10% randomized sample (1,084) of individuals were interviewed to evaluate the vaccination rate among healthcare workers with direct patient contact. RESULTS. Between September 23, 2008, and April 30, 2009, a total of 16,079 vaccinations were administered. Ninety-four percent (94.5%) of persons who were vaccinated received the vaccine in the first 7 weeks of the campaign. The randomized survey demonstrated an overall vaccination rate of 71.3% (95% confidence interval, 68.6%-74.0%) and a vaccination rate for employees with direct patient contact of 82.8% (95% confidence interval, 80.1%-85.5%). The main reason (25.3%) for declining the program vaccine was because the employee had received documented vaccination elsewhere. CONCLUSIONS. The methods used to increase participation in the recent immunization program were successful, and a randomized survey to assess participation was found to be an efficient means of evaluating the workforce's level of potential immunity to the influenza virus.