Emerging and re-emerging virus infections pose a threat to global health. Viruses mutate to inevitably evade the effects of pathogen-specific antivirals, and the time required to develop a vaccine specific for an outbreak virus leaves populations unprotected for months. Our strategy is to focus on broad spectrum antivirals for diverse acute virus infections: interferons (IFNs)-. IFNs- exert both direct antiviral effects in infected cells and modulate host immune responses to clear virus. Data will be presented providing evidence for the antiviral effects of IFNs-against influenza A viruses H5N1 and pandemic H1N1, the SARS coronavirus and ebola virus, in vitro and in clinical studies during outbreaks. The mechanisms whereby IFNs-exert their antiviral effects and override the inhibitory effects of viruses will be described.