The United States has a de facto moratorium on genetic gain-of-function experiments that could increase the transmissibility or pathogenicity of potentially pandemic agents such as the H5N1 avian influenza virus. In Europe, opinion among scientists is divided on the benefits and risks of such research for policymakers. A new report on these differences by the European Academies Science Advisory Council (EASAC; see will help to inform scientists and the public on this globally controversial research.

As well as risk–benefit assessment, the report addresses concerns such as scientific responsibility, research review and management systems, options for national and international biosafety and biosecurity advisory bodies, and the publication of sensitive information. It also highlights areas in which European Union regulations and best-practice guidelines need further consideration, notably those affecting the publication and export of research findings. We recommend an integrated approach to biorisk assessment and management, with responsibilities and action shared among researchers, institutions and funders.