Primary Objectives:~To evaluate the magnitude of the humoral immune responses to quadrivalent vs trivalent influenza vaccines in adults between the age of 50 and 64 years with a prior diagnosis of GOLD Stage C and D COPD (vs. those patients without COPD).~To demonstrate immunogenicity by measuring hemagglutination inhibiting antibodies (HI) against the components of viral antigens using seroconversion (≥4 fold increase over baseline titers) and sero-protection (HI titer of ≥40 against the vaccine components).~Secondary Objective:~To assess the degree of antibody response of COPD patients based on severity of disease as measured by FEV1.~To assess the impact of inhaled corticosteroids on the adaptive immune response after vaccination.
To evaluate the magnitude of the humoral immune responses to quadrivalent vs trivalent influenza vaccines in adults between the age of 50 and 64 years with a prior diagnosis of GOLD Stage C and D COPD vs. those patients without COPD.