Influenza is a serious infection occurring on an annual basis. About 5-20% of Americans are affected each year with more than 36,000 deaths and 200,000 hospitalizations. The elderly are among those at greatest risk for this infection, but have the lower rates of protection and antibody response to the influenza vaccine. On strategy to improve vaccine response is to increase the amount of antigen in the vaccine. The high-dose vaccine has four times the amount of hemagglutinin contained in the standard dose influenza vaccine.