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HealthScience

'Doomsday Virus' Not as Lethal as Feared, Researcher Now Claims

Influenza A virus (H5N1)

In the continuing controversy over the 2011 experiments with an ‘mutant’ strain of avian flu (H5N1) virus — making it airborne and potentially contagious to humans — lead virus researcher of growing notoriety, Ron Fouchier, told an audience of microbiologists that he did not believe that either the wild-type avian flu virus or his lab’s strain of the H5N1 flu were as lethal as others have supposed. The fatality rate is exaggerated,  he believes, because most cases that do not cause serious illness go undetected or unreported.

This comes in contrast to previous statements made by Fouchier, such as his statement to the journal Science in November of 2011: [This is] “probably one of the most dangerous virus you can make.”

Indeed, current WHO estimates are that the virus kills up to 60% of those who get it. To date, only 600 humans have contracted the avian flu, but more than half have died. The flu is almost exclusively one of chickens (the flu has killed hundreds of millions of chickens world wide, manly in SE Asia) and which only rarely jumps to humans. And, rarely does the virus spread from human to human.

The Controversy

This rarity of human to human transmission is largely so because the aH5N1 virus is not easily airborne (due to a lack of certain mutations). That is, until Fouchier (in the Netherlands) and another researcher, Kawaoka (in the US), made the virus airborne (or “aerosolized”) by spreading in between caged ferrets.

Speaking to an interviewer for The Influenza Times, Fouchier called the results “very bad news” and announced: “This virus is airborne and as efficiently transmitted as the seasonal virus.”

As a result of these reports and announcements to the press, the research was selected for official review by the National Science Advisory Board for Biosecurity (NSABB) which recommended that the papers be delayed in their  publishing until experts can review them and that key details be redacted (blacked out).

Despite cries of scientific censorship amongst some scientist groups, the researchers agreed to the NSABB requests.

Then, this past February, a special panel of the WHO, while agreeing that the publication should be delayed (which the major journals involved, Science and Nature, had already complied with), determined that the papers should then be published in full — unredacted.

The Confusion

Initial reports on the experiments (funded by USNAID) claimed that the virus became airborne (transmissible) after just five transfers amongst a group of ten ferrets. This was all it took before the strain developed enough gene mutations to make it contagious. Reports also implied that all transmissions (save for the first induced infection) of the virus occurred via the air.

In addition, other misreporting of the facts have occurred: a February 18,  ABC News report stated that  “all 40 ferrets” had died in the experiments. Since the earliest reports, the new strain of avian flu was dubbed the ‘Doomsday virus’ by the mainstream media.

At the ASM meeting in Washington, D. C. on February29, 2012, Fouchier revealed that the altered strain of virus made in his lab (Erasmus MC, Rotterdam) “does not kill ferrets” by the aerosol route.

Adding further to the confusion, Fouchier also stated that the virus is “more difficult to transmit” (between animals) than was previously described by he and his team.

The Clarification

In what appears to be an attempt to clarify his earlier, more emphatic statements, Fouchier told members of the American Society of Microbiologists (ASM):

‘There are a lot of misperceptions about what you can and can not conclude from these studies.”

Revealing some of the the actual details of the experiment, Fouchier reported that his team infected four ferrets (swabbed their noses) with the mutant strain, which then spread to three of four others in a nearby cage via the aerosol route. The (new) virus was then isolated from one of these ferrets, and used it to infect (via nasal swab) two other uninfected ferrets, who subsequently spread it to each of two ferrets in a neighboring cage. None of the exposed animals in this experiment died from the virus.

Fouchier did acknowledge that a second, smaller group of ferrets, whose lungs were directly infected by large doses of the  strain, did indeed “drop dead”.

Additionally, U.S. researcher Kawaoka (who also developed a more transmissible strain), stated in a January 2012, Nature comment that his lab’s mutated strain did not kill ferrets and was no more lethal than the strain that caused the 2009 pandemic, which was considered “mild”.

Responding to criticisms from officials that the virus would spread rapidly (“like wildfire”) if it ever escaped the lab, Fouchier emphasized that the mutant  strain failed to spread 100% of the time via the aerosol route, and that ferrets infected with the altered H5N1 were not more likely to spread the flu than ferrets infected with seasonal influenza strains. He further stated that his experiments showed that the mutant virus replicated more slowly and had much lower “peak levels” than in model animals with seasonal influenza.

“We have to conclude”, he said, “that this virus does not spread like a pandemic or seasonal influenza virus.”

This statement also seemed to be inconsistent with Fouchier’s reported comments at a Malta conference in November of 2011.

One Researcher Versus Real-Life Data

Attempting to further allay official concerns over the value of such experiments, and public fears that the virus could “wipe out half the human population”, Fouchier also stated his belief (based in part on his animal experiments) that previous exposure to seasonal influenza virus would offer some “cross-protection” against the H5N1 strain, if it ever were to escape from the lab.

However, following these public statements, NSABB member Michael Osterholm told Science Magazine*, that there was no evidence supporting Fouchier’s claims about cross-protection (and a lower fatality rate due to undetected cases) “beyond this animal model,  and we have an abundance of data from real life that speaks against it.”

Author Comment:

So much for resolving the confusion and clarifying the dangers of the virus.

Clearly, this is a significant difference of opinion here.

What is clear from the experiments, is that the virus did not kill the ferrets and is somewhat less transmissible than are typical seasonal flus.

What is clear in general, is that the researchers have expanded the range of the virus (into ferrets) and altered its mode of transmission (made it airborne).

How much cross-protection against the virus we actually have is a matter of debate.

* Some source material and all quotes used in this blog came from the Science (9 March, 2012) News Report ‘Surprising Twist in Debate Over Lab-Made H5N1’ by Jon Cohen

For further reading on these controversial experiments, check out this Science Mag on-line article : NSABB Members React to Request for Second Look at H5N1 Flu Studies or check out the other Planetsave.com articles on this topic (listed below the article)

Photo: Influenza A virus, the virus that causes Avian flu. Transmission electron micrograph of negatively stained virus particles in late passage. (Source: Dr. Erskine Palmer, Centers for Disease Control and Prevention Public Health Image Library)




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