May 3, 2012
Controversial Avian Flu Research Finally Published
Connie K. Ho for RedOrbit.com
A controversial report regarding avian flu research was finally published on May 3 in the journal Nature.
The research, which studies how the avian H5N1 influenza spreads among mammals, had been contested by a government review panel who wanted to stop the report from being published.
According to Med Page Today, the study finds four key mutations in a gene of the H5N1 avian flu that helps it adjust to mammals. The debate about the publication of the paper was based on fears that terrorist groups or criminals could use the findings to harm others.
"This information could be used by an aggressor and shows one of the building blocks for the development of a potential BW [biowarfare] weapon," highlighted the AFP on the report´s response to the danger of publicizing the information.
Flu and public health researchers argued that the study was important in informing the public to be prepared and aware of the virus.
"Our study shows that relatively few amino acid mutations are sufficient for a virus with an avian H5 hemagglutinin to acquire the ability to transmit in mammals," remarked Yoshihiro Kawaoka, a University of Wisconsin-Madison flu researcher, in a prepared statement. "This study has significant public health benefits and contributes to our understanding of this important pathogen. By identifying mutations that facilitate transmission among mammals, those whose job it is to monitor viruses circulating in nature can look for these mutations so measures can be taken to effectively protect human health."
The group of researchers had already identified a subset of viruses in some poultry in Egypt and parts of Southeast Asia. Kawaoka´s study on the H5N1 virus transmissibility found that there were unknown mutations that could pass. With these unknown mutations, he believes that it is important to continue the research to find out how the mutations function. The findings also show that the viruses that currently circulating in nature only need four mutations to the hemagglutinin protein to become a bigger risk to human health. The team looked at a laboratory-modified bird flu/human flu hybrid virus that could affect humans with a few mutations. They learned that the virus could be controlled by medical countermeasures like an H15N vaccine or oseltamivir, an antiviral drug.
"H5N1 viruses remain a significant threat for humans as a potential pandemic flu strain. We have found that relatively few mutations enable this virus to transmit in mammals. These same mutations have the potential to occur in nature," commented Kawaoka in the statement.
The H5N1 virus, since 2003, has affected at least 600 human and killed half of the people it´s infected. The virus, found mostly in Asia, can be transmitted in close proximity of fowl but it doesn´t easily transmit among humans. The flu depends on its ability to take control of host cells, make new virus particles that can then infect other cells, and transmit to other hosts. However, the flu virus must change its topography to adjust to new host species. As such, the protein hemagglutinin allows viruses to enter host cells and uses a “globular head” to bind to the host cell. The amino acids in the hemagglutinin can then unlock the host cell, allowing the virus to enter and spread the infection.
“The first clues about what properties of the HA protein, other than receptor specificity, might be important for mammalian airborne transmission,” described Vincent Racaniello, a virologist at Columbia University, in a Nature article. “It would have been a huge loss not to publish this.”
Overall, flu viruses are powerful in their ability to adapt to new animal hosts, exchange genetic information, and then mutate.
"It is hard to predict. The additional mutations may emerge as the virus continues to circulate."
As such, the study identifies the tool that allows H5N1 to transmit and helps them better understand the basis of the how the influenza virus transmits.
"Should surveillance activities identify flu strains accumulating additional key mutations, these emerging viruses should then be priority candidates for vaccine development and antiviral evaluation," mentioned Kawaoka in the statement.
Furthermore, it will help governments better develop their public health policies.
“That is an important public health message, we have to take H5N1 seriously. It doesn't mean it will become a pandemic, but it can," noted Malik Peiris, a virology professor at the University of Hong Kong who wrote an accompanying commentary, in an interview with Reuters.