Gene swapping makes new China bird flu a moving target

[Gert van der Hoek]

ANALYSIS-Gene swapping makes new China bird flu a moving target

Mon, 15 Apr 2013 09:34 GMT


* Deadly new H7N9 flu is mix of three avian flu strains

* Virus previously unknown in humans has now killed 13

* Genetic data available so far suggests H7N9 is unstable

By Kate Kelland, Health and Science Correspondent

LONDON, April 15 (Reuters) - A new bird flu virus that has killed 13 people in China is still evolving, making it hard for scientists to predict how dangerous it might become.

Influenza experts say the H7N9 strain is probably still swapping genes with other strains, seeking to select ones that might make it fitter.

If it succeeds, the world could be facing the threat of a deadly flu pandemic. But it may also fail and just fizzle out.

More: Alertnet

 

[NS1]

Re: Gene swapping makes new China bird flu a moving target

As previously discussed on April 10, 2013 in FluTracker's-hosted, GeneWurx original research based on precise RnR genetic evaluation of emergent H7N9 and the Cross Serotype Relationships to active human and avian influenza:

If this competent HA becomes less interested in the dead-ending, a potential exists for a reassortment to a more capable and compatible NA. The founding genetics of this current emanation of emergent H7N9 demonstrates multiple signal pathways toward N2 affinity with nominal secondary potential for mammal N8. The Gain of Function scalability ranges from the potentially lower risk H9N2 to the significantly higher risk donation from the circulating Vaccine-Escape, High-CFR H3N2.

That circulating human H3N2 has overseen mortality rates in the United States between 5 and 17 times last season's totals and between 200% and 300% of the previous state records in the states of Indiana, Minnesota and Pennsylvania. Though H3N2 is a long "understood" serotype with a multi-decade history of vaccine production, in the state of Indiana this year, 39% of the fatalities had confirmed vaccinations and another 34% conveniently were annotated as an "unknown" status. Only 27% of the fatalities were confirmed unvaccinated. Our reports from 2013 Week 13 (cumulative) are attached to this post.

The emergent H7N9 cases, while not 80% over 60 years old, demonstrate a weighting toward older citizens. Does this emergent H7N9 have something in common with the circulating human H3N2 that describes this affinity for older hosts or is the age skewing a small population anomaly that will self-correct as the sample size increases? If the emergent H7N9 does, in fact, prove to have interchange behaviour with sH3N2, will a convergent H3N2 NA reassortment be an attractive option to this competent HA and the currently stable 6 internal genes of the emergent H7N9?

• Sequence Analysis - Open-Access, Full-Text
• GISAID Citation