Flu researchers Yoshihiro Kawaoka and Ron Fouchier found themselves in the middle of a firestorm when, in 2011, they reported how, in separate experiments, they had created mutant strains of the H5N1 bird flu that were able to pass easily between ferrets -- mammals often studied to understand how flu passes between people.
On Wednesday, in a letter published in two leading scientific journals, the virologists and 22 coauthors explained why they are now planning to conduct similar experiments with another deadly bird flu: H7N9, which is circulating in China and has thus far killed 43 of the more than 130 people known to have been infected with it.
Scientists are concerned about H7N9 flu for a variety of reasons. So far, H7N9 hasn't been as deadly as H5N1, which as of early July had killed 377 people, according to the World Health Organization (nearly 60% of the known cases.) But unlike H5N1 infection, which sickens birds as well as people, H7N9 infection doesn't cause severe symptoms in the feathered set -- which means it can lurk in secret, giving public health workers little warning that it may soon strike.
What's more, some patients with H7N9 have not responded to treatment with antiviral drugs such as oseltamavir.
Along with their coauthors, Kawaoka, of the University of Wisconsin-Madison, and Fouchier, of the Erasmus Medical Center in Rotterdam in the Netherlands, proposed doing experiments that would help them understand what genetic changes create drug resistance in the virus and make it more transmissible and more deadly -- as well as why H7N9 doesn't sicken birds but does sicken people.
Such experiments might involve generating versions of H7N9 that are potentially dangerous, they wrote. Such research, known as dual-use research of concern, or DURC, worries critics who are concerned that new strains might escape the lab -- or that published studies describing the experiments might get into the hands of the wrong people.
The U.S. government has put together new guidelines for conducting H5N1 research, and in a separate letter also published in Nature and Science, authors from the Centers for Disease Control and Prevention, the National Institutes of Heath and the Department of Health and Human Services affirmed that any H7N9 work funded by the federal government would receive extra oversight.
Richard Webby, a flu researcher at St. Jude Children's Hospital in Memphis, Tenn., and a signer of the researchers' letter, said the letter was intended as a "heads-up to reiterate that we think the work is important."
"There are definitely people who won't agree," he said.
One critic, University of Minnesota infectious disease researcher Michael Osterholm, said that while such experiments do have scientific value, he remained concerned that scientists who weren't getting U.S. funding could still conduct dangerous work that would not be appropriately monitored.
He also argued that the researchers overstated potential benefits of the proposed H7N9 research.
"In discussions of H5N1, it was stated that this would change how we do [influenza] surveillance," said Osterholm, citing one example.
But it hasn't thus far, he added.
Webby's lab hasn't yet submitted any proposals for the new research, but he said he'd like to explore the genetic changes that occur in drug-resistant strains.
H7N9 activity in humans has been low in recent months, he said, but scientists expect more people to suffer from the bird flu as winter approaches.