In the past ten years, naturally occurring H5N1 avian influenza virus has proven lethal in nearly 60% of the 583 confirmed cases in humans. This highly deadly strain of the flu is currently being investigated in order to determine how flu viruses evolve from infecting only animals to being transmittable to humans.

Credit: sitox at iStockPhoto.com

Recently, researchers in leading influenza laboratories have found that viruses possessing a specific protein from the highly pathogenic H5N1 influenza viruses can become transmissible in ferrets, which are considered the best model for studying the flu because they contract the illness much the way humans do. In the course of the work, the scientists altered flu viruses to make them more transmissible, sparking a public debate over the importance and the dangers of such research. To publish the results of this work in a way that would allow them to be replicated by others could be extremely dangerous. Another fear is that the ferret-transmissible viruses may escape from the laboratories and lead to a flu pandemic.

In response to these concerns, Ron A.M. Fouchier of Erasmus MC in Rotterdam (the Netherlands), Adolfo Garcia-Sastre of Mount Sinai School of Medicine (New York, NY) and Yoshihiro Kawaoka of the University of Tokyo (Japan) and the University of Wisconsin (Madison) have agreed to voluntarily halt any research involving the generation of viruses from the avian flu H5N1 viruses that are more transmissible in mammals (Nature doi:10.1038.481443A; published online 20 January 2012). The researchers state that they hope the moratorium will provide time for scientists to “clearly explain the benefits of this important research and the measures taken to minimize possible risks... We realize that organizations and governments around the world need time to find the best solutions for opportunities and challenges that stem from the work.”

Little is known about what makes an influenza virus transmissible in humans, and this lack of understanding has been a major obstacle in preventing influenza pandemics. Scientists disagree, however, on whether research such as the work with H5N1 in ferrets will help prevent a pandemic or potentially help to create one. The research on influenza virus transmission has been conducted in laboratories that use the highest international standards of biosafety and biosecurity practices to prevent the release of transmissible viruses. Despite these precautions, the scientific community remains concerned. Several scientists selected by the World Health Organization will consider what the next steps should be at an international meeting next month.