中国のHabinの研究室で、致死率の高い2003年鳥インフルエンザA(H5N1)と感染率の高い2009年新型A(H1N1)インフルエンザの合成に成功。
Obtenido un virus de gripe con alta mortalidad y capacidad de transmisión
El experimento, en cobayas, combinó genes de la gripe A de 2009 con la aviar de 2003
Pretende adelantarse al riesgo de recombinación en la naturaleza
Emilio de Benito Madrid 3 MAY 2013 - 14:31 CET
Got a flu virus with high mortality and transmission capacity
The experiment, in guinea pigs, combined genes from 2009 flu 2003 avian
It aims to anticipate the risk of recombination in nature
Emilio de Benito Madrid 3 MAY 2013 - 14:31 CET
A laboratory of Harbin, northeastern China, keeps perfect pathogen facilities: combines the high lethality of avian influenza viruses of 2003 (H5N1) transmission with the ease-at least among the guinea-of which called swine flu or influenza A 2009, a H1N1. The work of the experiment realizes Science has published and has been quickly replicated by Nature.
Specifically, the study by researcher Chen Hualan H5N1 has taken as a base and has been introduced genes of H1N1. She's done in the laboratory, but the idea is that it is something that can happen in nature if both viruses in the same host match (a person or a pig, for example). And that, the authors note, is not so rare. Although it seems forgotten, H5N1 has not disappeared. It has caused a disaster in Southeast Asian farms with millions of birds killed and many were killed, and had, at the last count of the World Health Organization on April 26, 374 deaths since 2003 (13 of them this year ), with a fatality rate (proportion of infected dead) of 59.6%. On the other hand, H1N1 has already demonstrated its ability to spread in 2009 when an outbreak in Mexico has spread throughout the planet in three months. Both, that is still circulating and, for example, is part of the virus against which influenza vaccines produced every year since then, including scheduled for the winter of 2013.
What he has done has been exchanging Chen entire genes of H5N1 by H1N1 and created up to 127 recombinant viruses. This process is common in nature, and is one of the ways that are adapted and modified viruses (the other is through mutation). Viruses, like bacteria, are relatively simple organism. The influenza only have eight genes, and are quite promiscuous: when matching a congener, are interrelated. In the world of viruses that means they share genetic material.
China researcher then used their copies to infect guinea pigs, and measured how easily the virus is transmitted from rodents affected the healthy. This helped in determining that it was enough that the original H5N1 To exchange two genes specific to H1N1 to become easily transmissible. And it was not necessary that the exchange out of both at once was enough to do it with one or the other. This seems like a bad sign: the recombination (the name given to the movement of genes) easier.
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The work has been published without apparent fault in the most renowned scientific journals, which clashes with what happened a year ago when other researchers did something similar: identify which three mutations in the H5N1 sufficient for it to become easily transmissible among ferrets (which is another of the animals that are used as a model because what happens in these animals, when flu is concerned, usually human application). Chen herself has stated that he wanted to do his essay also in ferrets, but could not, among other things because now is overturned on H7N9.
What does that has happened, like a year ago, is that there has been criticism that the work is published. The fear there is that terrorist groups might try to make a biochemical weapon following the work of Chen (or colleagues). Although this is not as clear. Guinea pigs have a significant difference with respect to humans: their lungs have receptors for avian influenza virus, while the people have only mammals adapted viruses. This explains the strangeness whenever there is a jump between species such as the recent H5N1 or H7N9 and, at once why it seems that the expansion of both pathogens is contained, and that human to human transmission is not easy. This difference is pointed out by some experts. Although the ability to pass can be achieved with a change of genes, as seen in the study, the actual infectivity in humans depends on the entire set, and it has not been demonstrated.
Chinese researcher says his goal is to anticipate a possible risk. The H5N1 is still active in Cambodia, Vietnam, China and Egypt, and all of these countries are also occupies territories H1N1. Having a model to investigate before it is exemplary in nature can be useful if the pathogen does not escape from the facility. China has made great strides to gain quality and reliability for their work (for example, a clear leader in the H7N9 research, something that did not happen with H5N1 or SARS). But that did not prevent some misgivings. For example, Simon Wain-Hobson, a virologist at the Pasteur Institute in Paris, who has told Science that the work-a lot of quality, yes, "is very dangerous."
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