Comparison of 4 Influenza Vaccines in Seniors

Based on information from several years of looking at Influenza vaccination doctors know that: * Older adults suffer the worst illness and most deaths caused by Influenza illness of all age groups. * Older adults do not seem to get as good a level of protection as younger adults after getting the usual seasonal Influenza vaccine. Because of this information doctors wonder if one of the new seasonal Influenza vaccines is more effective or more acceptable. This study has been designed to answer some of these questions. On this study doctors will compare 2 new vaccines against the usual seasonal influenza vaccine for protectiveness using several different testing methods (including the usual tests) and for acceptability.