The researchers started with a strain called influenza virus A/Indonesia/5/2005, which has infected and killed a number of humans. They first changed three proteins to make it more compatible with mammals' tissues and body temperatures. And then they introduced it into the nose of a ferret.
Ferrets are the best model we have for studying influenza—they are similarly susceptible to it and can spread it by sneezing—and have been used to study the infection since the 1930s. But that does not mean that they are a perfect flu foil for humans. "An H5N1 virus strictly adapted for ferret transmissibility may not be entirely relevant to humans," Fauci and Collins wrote in their essay.
The experimental ferrets Fouchier used did not pass the disease directly to one another, as would occur among humans in a real-world outbreak. Instead, during the first six of the 10 transmissions, researchers dropped the strain into the ferret's nose and then later swabbed the nasal area to collect the virus—with any new mutations—to be given to the next ferret. In the final few transmissions, instead of swabbing the nose, researchers made each animal sneeze, then collected the contents and placed them directly in the nose of the next ferret. Follow-up experiments showed that when an uninfected ferret was placed near one of these infected subjects—sharing air but not able to make physical contact—the uninfected ferret often caught the illness (looking tired and not eating much) but did not die from it.
As Fouchier and his co-authors noted, none of the ferrets that received the newly transmissible virus died from the infection. (And only one in eight of the animals given an earlier form of the virus, via the nose inoculation, died from the illness.) This shift in virulence mirrors the pattern that has often played out in human pandemics: as a virus becomes more easily transmissible, it becomes less deadly. In the experiments, the viruses were also treatable with common antiviral drugs.
What were the mutations that made the virus able to infect other ferrets just by breathing the same air? Four of the five mutations changed the virus's surface protein (hemagglutinin), which plays a role in allowing H5N1 to gain entry into host cells. And the fifth mutation boosted its ability to reproduce its genetic information.
Two of the mutations identified by Fouchier are already quite common in wild strains of H5N1 in birds and occasionally show up in the same strain, according to Smith's study of some 4,000 strains. As Smith and his colleagues pointed out in their paper, that means that some strains might need only three more mutations to become easily contagious among mammals. These three other mutations are rare in H5 strains (although two of them were present in the H2 and H3 pandemics of 1957 and 1968, respectively), so they are likely harmful to the virus while it resides in its bird host. Smith and his team created mathematical models to try to figure out how likely it was that these three mutations could occur in a human host. But without further research, they could only speculate that it was possible, they noted.
Trying to assess the likelihood of an outbreak of this virus in humans is about as easy as "predict[ing] an earthquake of tsunami," Smith said at the press briefing. "We now know that we're living on a fault line," thanks to Fouchier's research. "And it's an active fault line."
That prediction problem, however, suggests that much more research needs to be done on just how these viruses mutate within hosts. They also suggest increasing surveillance to do deeper genetic sequencing of circulating strains to look for less common mutations that might increase the odds the virus will jump to a new species host.
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Add CommentAgreed. The best defense is a good offense. And without scientific knowledge of the strains we have literlly NO offense against such "bugs". Any one who disagrees I recommend reading the Art of War
Reply | Report Abuse | Link to this"the general who wins a battle makes many calculations in his temple ere the battle is fought. The general who loses a battle makes but few calculations beforehand. Thus do many calculations lead to victory, and few calculations to defeat: how much more no calculation at all! It is by attention to this point that I can foresee who is likely to win or lose." -Sun Tzu
Why were Mr. Fourier's work kept a secret for so long?
Reply | Report Abuse | Link to thisWhy even waste the money, the whole thing was a bad bird joke for media attention and public tax funding!
Reply | Report Abuse | Link to thisWe have so many other bigger problems to solve, it's hardly worth a comment, never mind an article.
A Drug Cure will always come too late to save Humanity
Reply | Report Abuse | Link to thisIn 1997 the pandemic was stopped in its tracks in Hong Kong. The system adopted was not reliant upon a drug cure but that prevention was better than cure. It worked and Ken Shortridge who devised the strategy was given the Asian equivalent of the Nobel Prize in medicine, The Prince Mahidol Award. By doing this Prof. Shortridge stopped a bird flu pandemic starting and which had the propensity to kill millions (the only one ever to do so and prevent the deaths of incalculable numbers). The premise was, ‘don’t let it start in the first place’.
Why has the establishment therefore forgotten the first dictum of medical health that ‘prevention is better than cure?’
http://avian-influenza.cirad.fr/content/download/1931/11789/file/Kennedy-F-Shortridge.pdf
And why have those who are advocating a drug cure not taken on-board this system that has worked? This question is postulated because the Swine Flu pandemic showed that with reference to the Spanish Flu in 1918 which took up to 100 million lives, that a cure would come too late. In this respect it was not until 7 months 1 week that a vaccine was created and then it had to be manufactured and thereafter distributed to the masses (a logistics nightmare). In the second wave of the Spanish Flu, after the virus had mutated into a human-to-human killer, it did its worst between week 16 and week 26, some 1 month 1 week before a cure was found for the Swine Flu pandemic.
Therefore whatever way we look at it a drug vaccine will come too late to save us, no matter who you are from the president of the United States downwards. Fact not fiction.
Margaret Chan, Director-General of the WHO says that it is only a matter of time not when the killer virus will emerge - may be next week, next month, next year or whenever; but it will happen sometime and such a pandemic according to pandemic researchers is overdue. Therefore we are living on borrowed time and we have to adopt Prof. Shortridge's strategy for the good of all humanity.
Dr David Hill
Chief Executive
World Innovation Foundation
I would imagine if terrorists used these papers to replicate the virus, it may escape their bio containment protocols (if they even exercise containment protocols), leaving their labs and infecting their scientists and inhabitants of that geographic region. Whether the military and world health officials from various governments have enough intel to identify these clandestine operations, move in, and contain such an outbreak, "sterilizing" the area of infection, remains to be seen.
Reply | Report Abuse | Link to thisyes, it is a danger
Reply | Report Abuse | Link to thisBrought to you by the makers of the flu vaccines, nothing like a bit of panic to bring up sales!!
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