This is a phase 3, randomized, controlled, open-label study with two vaccine regimens.
The study will assess the relative safety and immunogenicity of vaccine regimens comparing adjuvanted versus non-adjuvanted formulations of A(H1N1) inactivated influenza virus vaccine in subjects with Chronic Pulmonary Disease, Chronic Heart Disease, or Diabetes Mellitus, and to compare the safety and immunogenicity data with a contemporaneously enrolled control group of age-comparable, healthy subjects.
Because certain individuals may be hypo-responsive to influenza vaccination, additional studies with high-risk groups are warranted in order to determine the optimal vaccine formulation and dosing schedule for the prevention of novel H1N1 virus infection.