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Bird flu researcher reveals details of work

TORONTO - A scientist at the centre of a raging controversy over bird flu transmission studies has broken his silence, in the process revealing information about his study that has not been made public previously.

TORONTO - A scientist at the centre of a raging controversy over bird flu transmission studies has broken his silence, in the process revealing information about his study that has not been made public previously.

In a commentary in the journal Nature, flu virologist Yoshihiro Kawaoka argued the work he and other high level influenza scientists do to try to puzzle out why some flu viruses spread in humans while others don't is too important to be shelved.

"Our work remains urgent — we cannot give it up," wrote Kawaoka, who up until now has made no comment on the controversy that is pitting flu scientists against the community of biosecurity experts, some of whom insist no further transmission studies on the dangerous H5N1 flu virus should be undertaken.

In his commentary, Kawaoka revealed that his laboratory at the University of Wisconsin-Madison made a hybrid virus, fusing the hemagglutinin protein (the H in a flu virus's name) from H5N1 onto the human H1N1 virus that caused the 2009 pandemic.

The H1N1 virus spreads easily among people but H5N1 currently does not.

They found the viruses came together readily, and spread easily among ferrets kept in separate cages. Ferrets are considered the best animal model for predicting how a flu virus will act in humans and that type of study is meant to replicate the conditions under which flu viruses transmit among humans.

But while it was highly transmissible, the mutant virus did not kill the ferrets, Kawaoka reported. In fact, it was no more pathogenic to the animals than the 2009 H1N1 virus, he said.

"Our results ... show that not all transmissible H5 HA-possessing viruses are lethal," he wrote. HA is the short form for hemagglutinin used by flu scientists.

Nature, which plans to publish Kawaoka's paper, acknowledged it had given him dispensation to release information about this work. Normally journals will not publish studies if the findings have already been reported elsewhere, including in the mainstream media.

Spokeswoman Rachel Twinn said Nature decided it was in the public interest to allow Kawaoka to share details of his findings at this time.

Kawaoka — who also has an appointment at the University of Tokyo — runs one of two labs caught up in this roiling controversy. The other is run by Dutch virologist Ron Fouchier of Erasmus Medical Centre in Rotterdam.

Fouchier has been front and centre in this debate. And before now, much more was known about his work because he reported on it at an influenza conference in Malta in the fall. (Journals' pre-publication bans don't apply to presentations made to scientific conferences.)

Fouchier's team forced evolution of an H5N1 virus in ferrets, getting it to the point where it easily transmitted among the animals.

It was a full H5N1 virus — it was not a hybrid — and it was fatal to at least some of the animals. His paper is to be published in Science.

But before Science and Nature could publish the works, a panel of biosecurity experts urged the U.S. government to ask the journals not to publish the full works, saying to do so would be to print recipes for potential bioterror weapons.

The journals and the scientists have grudgingly agreed. But the flu community and some others in the science world have objected to the decision, saying to hold back the full details of the studies will impede science that needs to be done.

In the hopes of creating room for a compromise, last week 39 leading flu scientists — including Kawaoka and Fouchier — announced they would observe a voluntary 60-day moratorium (from Jan. 20) on H5N1 transmission studies. The idea was to give the global community time to sort through the troubling issues the work raises.

The World Health Organization, which has been asked to help mediate the problem, has said it will convene a meeting of technical experts in Geneva in mid February, probably Feb. 16-17.

The WHO's point person on the issue, Dr. Keiji Fukuda, has said the meeting will be small, involving fewer than 50 people. The scientists who did the studies as well as scientists from WHO's network of flu laboratories will be invited to attend.

A representative of the U.S. biosecurity panel — the National Science Advisory Board on Biosecurity — will also be invited to attend, Fukuda has said.

In his commentary, Kawaoka argued that trying to disseminate the full details of his and Fouchier's work on a need-to-know basis — the U.S. proposal — will be unworkable.

And he said redacting the studies won't eliminate the possibility that the information will become public.

"There is already enough information publicly available to allow someone to make a transmissible H5 HA-possessing virus," he warned.