Induction and evasion of type I interferon responses by influenza viruses

Influenza A and B viruses are a major cause of respiratory disease in humans. In addition, influenza A viruses continuously re-emerge from animal reservoirs into humans causing human pandemics every 10–50 years of unpredictable severity. Among the first lines of defense against influenza virus infection, the type I interferon (IFN) response plays a major role. In the last 10 years, there have been major advances in understanding how cells recognize being infected by influenza viruses, leading to secretion of type I IFN, and on the effector mechanisms by how IFN exerts its antiviral activity. In addition, we also now know that influenza virus uses multiple mechanisms to attenuate the type I IFN response, allowing for successful infection of their hosts. This review highlights some of these findings and illustrates future research avenues that might lead to new vaccines and antivirals based on the further understanding of the mechanisms of induction and evasion of type I IFN responses by influenza viruses.