Influenza viruses present challenges to healthcare systems and vaccination co-ordinators around the world. Global surveillance of this potentially devastating pathogen is ongoing and vaccine producers alter their products accordingly each year. While the impact of influenza pandemics is profound and such events are planned for, the impact of seasonal epidemic events should not be underestimated. In some cases, the cumulative death toll from seasonal outbreaks is greater than that caused by far rarer pandemic events. A critical programme for limiting the impact of seasonal outbreaks in the UK is the vaccination of front line healthcare workers against influenza. This article will outline the clinical impact of influenza viruses and examine why healthcare staff need to be vaccinated.