2 Clinical Trials for Various Conditions
Unlike most influenza viruses, the 2009 H1N1 virus has affected people between 5 and 40 years old more often than people 60 years old or older. It may be that older people have had greater exposure to previous strains of H1N1 influenza, and this previous exposure protects them from infection. This study will examine how older people respond to a version of the H1N1 virus vaccine that includes a live, noninfectious version of the virus.
The purpose of this study is to evaluate the immune response produced by a seasonal live attenuated influenza vaccine (LAIV) when compared to placebo. The initial vaccination will be followed 2 months later by an inpatient trial evaluating safety, infectivity, clinical response, and viral shedding after exposure to the wild-type A/California/2009-like influenza challenge virus.