Reducing absenteeism in a county school system through school-based influenza vaccination clinics

The Kanawha-Charleston Health Department (KCHD) is located in Charleston, West Virginia, serving the state's largest metro area with a population over 200,000. As reported last year, KCHD partnered with the county school system to implement school-located vaccination (SLV) clinics as a delivery system for the influenza vaccinations in 2009, 2010, and 2011. With a sustainable influenza immunization program in place, KCHD's next step is to demonstrate that the program has been effective in decreasing illness. Detailed data was collected from each SLV to determine uptake rates by school and level (primary, middle, or high). Absence data from 2006-2011 was aggregated by individual school, school level, CDC ILI week, and year. These data were then analyzed together to determine if immunization rates had any measurable effect on absence. Results of this analysis vary widely depending on school and grade level. With the highest uptake rates and the steadiest absence rates, elementary schools demonstrated a significant (a=.05) reduction in expected absence during peak influenza season. Baseline data suggested an average increase of absenteeism during peak influenza season of 14.2 percent in elementary schools. During the two intervention years, the absence rate increased only 5.8 percent at this time, a reduction in expected absenteeism of nearly 60 percent. While continued data collection and analysis is warranted, the results of this study suggest that SLVs can decrease influenza illness in schools. Importantly, the Kanawha-Charleston Health Department has successfully demonstrated that it is possible to create a self-sustaining, school-based influenza immunization program without external funding.