Strains of bird flu that could spread among humans have been created in the lab - and now full details on just how this was done have been published openly, raising fears that the research could be used by terrorists to craft a deadly bio-weapon plague.
Bird flu, or H5N1, has killed more than half of the 600 people it is known to have infected, but it cannot spread easily between people. So Yoshihiro Kawaoka of the University of Wisconsin-Madison set out to find whether H5N1 could evolve in the wild into a form that was transmissible between humans.
Kawaoka’s FBI-approved team first created thousands of mutant versions of H5N1. From these they identified a version that could stick to cells in the human nose and throat and then combined this with the strain from the wild that caused the 2009 pandemic. With this hybrid virus, the scientists infected ferrets and watched for when the virus evolved a strain that could spread through the air and infect healthy ferrets in neighbouring cages.
According to Kawaoka, the study shows that relatively few mutations are required for the virus to acquire the ability to transmit between mammals, including humans. The strain created during Kawaoka’s research is less severe than the one that caused the 2009 pandemic, it is susceptible to Tamiflu and it did not kill any of the ferrets in the experiments.
But there may be further strains not studied that have the ability to evolve transmissibility. In fact, the researchers have already spotted strains with one of the mutations they identified in Egypt. As Laurence Fishburne’s character in Contagion says: “Someone doesn’t need to weaponise the bird flu. The birds are doing that.”
Kawoaka is less dramatic, claiming that the results can help authorities to prevent or prepare for an outbreak.
"This study has significant public health benefits and contributes to our understanding of this important pathogen,” he said. “By identifying mutations that facilitate transmission among mammals, those whose job it is to monitor viruses circulating in nature can look for these mutations so measures can be taken to effectively protect human health."
It is an argument made repeatedly over the past few months by Kawoaka and his colleague Ron Fouchier, a researcher at the Erasmus Medical Center in Rotterdam and author of another blocked bird flu paper. Although Kawaoka’s research is now published, Fouchier’s remains under wraps, even though Science magazine has said it will publish the work. The concerns over the researchers’ studies came from the US National Science Advisory Board for Biosecurity (NSABB).
The body’s decision to block the research kickstarted months of tense discussion between virologists, security experts and journal editors. Last month, the NSABB reversed its controversial decision after Kawaoka and Fouchier amended their papers. “The revised papers had more clarity on risks and benefits,” said the NSABB’s Paul Keim, who added that the board comprises scientists, not “generals and colonels and majors”.
Fouchier admitted at an emergency conference convened in April to discuss the controversy, that most of the extra 1000 words he added to his paper dealt with the level of biosecurity in place during the research.
The Dutch virologist explained that due to the biosecurity conditions in place, if an accident were to happen, “the public won’t be exposed, but the individuals in the laboratory will be”. ®