2009H1N1 Influenza in Immunocompetent and Immunocompromised Patients

The treatment and prevention of influenza virus infection has been associated with two major challenges that are exemplified by 2009H1N1 as well as previous pandemics. The constant evolutionary pressure on the influenza virus can result in novel strains which may not be optimally protected by vaccines or currently approved antivirals. Selection for antiviral resistance mutations can occur over time. Prolonged virus shedding, selection for resistance mutations, and cross resistance, can be exacerbated and problematic in immunocompromised patients. This review will cover 2009H1N1 infection in immuno-competent and immunocompromised individuals. Influenza continues to be a major public health concern and these challenges make influenza a suitable area for new vaccine and antiviral approaches.