Influenza

Influenza viruses are important human pathogens causing yearly epidemics and severe disease in humans, despite the availability of vaccines and antivirals. Complicated influenza virus infections result in primary viral pneumonia or secondary bacterial pneumonia and in some instances, death, especially in high-risk groups. Influenza pandemics can be of devastating consequences if not treated or prevented and they occur approximately 3 times per century when viral antigens present in avian circulating strains are being acquired by human influenza strains. Several pathogenic determinants have now been mapped for influenza virus strains, as well as several mutations associated with host adaptation from avian to mammalian hosts, but we still lack basic knowledge on these processes as well as on the mechanisms responsible for efficient transmission and for severe disease. Better vaccines and new antivirals will be needed for the mitigation of seasonal influenza and of potential future influenza virus pandemics.