Past research has made the H5N1 virus transmissible in ferrets.{credit}Sara Reardon{/credit}

As the US public frets about the recent transmission of Ebola to two Texas health-care workers, the US government has turned an eye on dangerous viruses that could become much more widespread if they were to escape from the lab. On 17 October, the White House Office of Science and Technology Policy (OSTP) announced a mandatory moratorium on research aimed at making pathogens more deadly, known as gain-of-function research.

Under the moratorium, government agencies will not fund research that attempts to make natural pathogens more transmissible through the air or more deadly in the body. Researchers who have already been funded to do such projects are asked to voluntarily pause work while two non-regulatory bodies, the National Science Advisory Board for Biosecurity (NSABB) and the National Research Council, assess its risks. The ban specifically mentions research that would enhance influenza, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). Other types of research on naturally occurring strains of these viruses would still be funded.

This is the second time that gain-of-function research has been suspended. In 2012, 39 scientists working on influenza agreed to a voluntary moratorium after the publication of two papers demonstrating that an enhanced H5N1 influenza virus could be transmitted between mammals through respiratory droplets. The publications drew a storm of controversy centred around the danger that they might give terrorists the ability to create highly effective bioweapons, or that the viruses might accidentally escape the lab. Research resumed after regulatory agencies and entities such as the World Health Organization laid out guidelines for ensuring the safety and security of flu research.

The OSTP’s moratorium, by contrast, is mandatory and affects a much broader array of viruses. “I think it’s really excellent news,” says Marc Lipsitch of Harvard University in Cambridge, Massachusetts, who has long called for more oversight of risky research. “I think it’s common sense to deliberate before you act.”

Virologist Yoshihiro Kawaoka of the University of Wisconsin–Madison, who conducted one of the controversial H5N1 gain-of-function studies in an effort to determine how the flu virus could evolve to become more transmissible in mammals, says that he plans to “comply with the government’s directives” on those experiments that are considered to be gain-of-function under OSTP’s order. “I hope that the issues can be discussed openly and constructively so that important research will not be delayed indefinitely,” he says.

The NSABB, which has not met since 2012, was called back into action in July, apparently in response to a set of lab accidents at the US Centers for Disease Control and Prevention in which lab workers were exposed to anthrax and inadvertently shipped H5N1 virus without proper safety precautions. The NSABB will spend most of its next meeting on 22 October discussing gain-of-function research, and the National Research Council plans to hold a workshop on a date that has not yet been set. Lipsitch, who will speak at the NSABB meeting, says that he plans to advocate for the use of an objective risk-assessment tool to weigh the potential benefits of each research project against the probability of a lab accident and the pathogen’s contagiousness, and to consider whether the knowledge gained by studying a risky pathogen could be gained in a safer way.

Correction: This post has been changed to specify that Yoshihiro Kawaoka’s 2012 gain-of-function research increased the transmissibility of H5N1.