Influenza and pneumonia are the fifth leading cause of death in the United States, the leading cause of vaccine preventable death, and the leading cause of infection related deaths among nursing home residents(Nace, Drinka et al.2010). Each year, an estimated 36,000 individuals die from seasonal influenza and over 90% of these deaths occur among older adults, primarily the frail older adults residing in LTC settings(Fiore,Uyeki et al. 2010).Vaccination is the most effective means of preventing influenza (Nichol and Treanor 2006). Despite increasing success in immunizing LTC residents though, outbreaks continue to occur annually with case fatality rates ranging between 5-55% (Nace 2008). Older adults have a reduced response to influenza vaccination, in part due to age related immunosenescence (Keitel, Atmar et al. 1121; Skowronski, Tweed et al. 2008). It is widely recognized that more effective vaccine options are needed for frail older adults. One option is to increase the hemagglutinin (HA) dose in influenza vaccines in an effort to increase antibodies to hemagglutinin. To date, no studies have evaluated the effectiveness of the HDIV among LTC residents.
