New interventions to increase influenza vaccination rates in health care workers

Background: The most effective strategy for avoiding nosocomial influenza outbreaks is through vaccination of health care workers (HCWs). In Spain, HCW vaccination coverage rarely exceeds 25%. The objective of this study was to determine whether an active vaccination campaign promoting communication among HCWs increased influenza vaccination coverage rates and permitted a shorter campaign. Methods: This was a before-after trial, comparing free mobile vaccination teams without and with strategies promoting HCW involvement by means of weekly educational and promotional messages through electronic mail, including 2 prize draws for vaccinated HCWs and a Web page including pictures of vaccinated HCWs and all senior hospital management. Weekly coverages were publicized, the staff of mobile units was increased, and their routes in the hospital were advertised. The study population was >4500 HCWs (permanent and temporary staff) at a Spanish university hospital during the 2007-08 and 2008-09 influenza seasons. Results: Coverage was 23% (95% confidence interval [CI], 22.5%-24.9%) in the 2007-08 season and 37% (95% CI, 34.7%-37.4%) in 2008-09 season. The vaccination rate was highest in HCWs aged >= 65 years and in physicians. The weekly vaccination rates were significantly higher for the 2008-09 season compared with the 2007-08 season except for the first and third weeks; for example, in week 2, the rate was 1.7 HCWs per 100 persons-week (95% CI, 1.3-2.1) in 2007-08, compared with 3.7 HCWs per 100 persons-week (95% CI, 3.2-4.4) in 2009-09. Rate increases were concentrated in the first weeks of the program, with a peak occurring in week 3 during the 2007-08 season and in week 2 during the 2008-09 season. Conclusion: This intervention improved influenza vaccination coverage of HCWs and allowed more rapid achievement of higher coverage.