Changes in influenza vaccination rates among healthcare workers following a pandemic influenza year at a Japanese tertiary care centre

SummaryBackgroundAlthough influenza vaccination, which is a key part of a control plan to prevent nosocomial influenza transmission, is recommended for all healthcare workers (HCWs), the achievement of a high influenza vaccination rate among HCWs is a challenge. In Japan, there are limited data on influenza vaccination rates among HCWs. Moreover, the effect of pandemic influenza on influenza vaccination rates among HCWs following a pandemic year remains unclear.AimTo determine influenza vaccination rates among HCWs at a tertiary medical centre in Japan, and to evaluate the need for further interventions to enhance the vaccination rate among HCWs.MethodsThe 2005–2010 influenza vaccination rates among HCWs at a 550-bed, tertiary care centre in Sapporo, Japan were reviewed retrospectively using the hospital’s occupational health service database.FindingsThere was a gradual increase in the seasonal influenza vaccination rate in this population from 2005 to 2010, and a high vaccination rate among HCWs during the 2009–2010 pandemic H1N1 influenza season. However, the seasonal influenza vaccination rate in 2010–2011 was significantly lower than that for the pandemic vaccine in 2009–2010, with doctors having the lowest vaccination rate among all HCWs.ConclusionPandemic influenza may not have a sustained effect on the uptake of influenza vaccination in subsequent years. Thus, vaccination rates among HCWs after a pandemic year still need to be monitored, and the implementation of interventions such as a mandatory vaccination programme should be considered to maintain consistently adequate vaccination rates.