The World Health Organization says it is worried about recent studies showing how the H5N1 virus could be adapted, making it more transmissible between animals and potentially, humans.

It issued a statement Friday indicating that it is concerned about the potentially negative consequences of this type of research into avian influenza, should it be misused.

On Dec. 20, the U.S government asked scientific journals and two research teams not to publish details of controversial studies on the bird flu virus over fears the data could fall into the wrong hand and have dire consequences. Scientists had mutated the H5N1 avian flu virus to the point where it became highly transmissible in ferrets and were set to publish their results.

WHO concedes that this type of research, though potentially dangerous, is necessary. "WHO also notes that studies conducted under appropriate conditions must continue to take place so that critical scientific knowledge needed to reduce the risks posed by the H5N1 virus continues to increase," it said in a release. "Such research should be done only after all important public health risks and benefits have been identified and reviewed, and it is certain that the necessary protections to minimize the potential for negative consequences are in place."

WHO also encourages scientists to abide by the rules of the Pandemic Influenza Preparedness Framework, which, established in May 2011, aims to encourage virus sharing between countries, collaborative research and best scientific practices in pandemic research. It acknowledged that although the scientists whose research made headlines last week begun their study prior to the establishment of the framework, it hopes they will abide by its new guidelines.