Friday, February 1, 2013

Making influenza more efficient: flu virus engineering resumes

Declan Butler, at Nature, writes:
The move follows a large international workshop convened on 17–18 December by the US National Institutes of Health in Bethesda, Maryland, to discuss ‘gain-of-function research’ — that intended to increase the transmissibility, host range or virulence — in H5N1 viruses, and the development of US rules for stricter oversight of research in this area. The proposed rules require an assessment of, for example, whether the scientific aims of such studies could be addressed using alternative, less-risky approaches, and whether biosafety and biosecurity risks can be adequately mitigated. They are expected to enter into force soon, allowing scientists working in the United States or on US-funded grants to restart such research.
The groups that published the original research have outlined a suite of possible follow-up experiments, including a search for other combinations of mutations that would allow H5N1 to transmit between mammals — which could answer basic-science questions and, they argue, aid efforts to watch for dangerous mutations in the wild.
Two papers discussing influenza engineering were published last summer; one in Nature and one in Science.  At first glance, you'd assume they're another case of competitive research completing the same project almost simultaenously (a very common happenstance), but the Science team from Erasmus writes that "the viruses that caused the major pandemics of the past century emerged upon reassortment (that is, genetic mixing) of animal and human influenza viruses".  They continue to explain that viruses generated through reassortment events don't work very well in ferret models, acknowledged that limitation, and continued to explore other genetic alterations that increase ferret-to-ferret transmission. On the other hand, the Nature team didn't acknowledge any limitation of viruses created by genetic reassortment, and actually base their study around viruses generated through that method, which according to the Erasmus team shouldn't work very well.

If anyone can explain this better to me, please let me know.