H5N1 transmissibility paper published

Nature published a revised version of the first of two studies on H5N1 transmissibility in mammals on Wednesday after over four months of debate among academics and government officials about the potential for misuse of the research for harmful purposes. Researchers at the University of Wisconsin and colleagues engineered an influenza strain that expressed a mutant form of the avian influenza (H5N1) hemagglutinin (HA) protein and was transmissible in a ferret model of influenza infection, according to the study. The strain's genome comprised seven genes from the 2009 pandemic H1N1 virus and a gene encoding the H5N1 HA protein with four mutations. In ferrets, the new strain replicated efficiently, caused lung lesions and weight loss, but did not cause mortality.

The authors wrote that the results indicate the HA protein from H5N1 "can convert to an HA that supports efficient viral transmission in mammals," but they said they do not know whether the four mutations in H5N1 HA would "render a wholly avian H5N1 virus transmissible." The authors added that the mutations could be useful for identifying circulating H5N1 viruses that have pandemic potential. ...