Featured Research

from universities, journals, and other organizations

Bird flu mutation study offers vaccine clue

Date:
April 8, 2013
Source:
Imperial College London
Summary:
Scientists have described small genetic changes that enable the H5N1 bird flu virus to replicate more easily in the noses of mammals.

The bird flu virus H5N1, in gold, is seen among cells known as MDCK, in green.
Credit: Image courtesy of Imperial College London

Scientists have described small genetic changes that enable the H5N1 bird flu virus to replicate more easily in the noses of mammals.

Related Articles


So far there have only been isolated cases of bird flu in humans, and no widespread transmission as the H5N1 virus can't replicate efficiently in the nose. The new study, using weakened viruses in the lab, supports the conclusions of controversial research published in 2012 which demonstrated that just a few genetic mutations could enable bird flu to spread between ferrets, which are used to model flu infection in humans.

Researchers say the new findings could help to develop more effective vaccines against new strains of bird flu that can spread between humans.

"Knowing why bird flu struggles to replicate in the nose and understanding the genetic mutations that would enable it to happen are vital for monitoring viruses circulating in birds and preparing for an outbreak in humans," said Professor Wendy Barclay, from the Department of Medicine at Imperial College London, who led the study.

"The studies published last year pointed to a mechanism that restricts replication of H5N1 viruses in the nose. We've engineered a different mutation with the same effect into one of the virus proteins and achieved a similar outcome. This suggests that there is a common mechanism by which bird flu could evolve to spread between humans, but that a number of different specific mutations might mediate that."

Bird flu only rarely infects humans because the human nose has different receptors to those of birds and is also more acidic. The Imperial team studied mutations in the gene for haemagglutinin, a protein on the surface of the virus that enables it to get into host cells. They carried out their experiments in a laboratory strain of flu with the same proteins on its surface as bird flu, but engineered so that it cannot cause serious illness.

The research found that mutations in the H5 haemagglutinin enabled the protein to tolerate higher levels of acidity. Viruses with these mutations and others that enabled them to bind to different receptors were able to replicate more efficiently in ferrets and spread from one animal to another.

The results have important implications for designing vaccines against potential pandemic strains of bird flu. Live attenuated flu vaccines (LAIV) might be used in a pandemic situation because it is possible to manufacture many more doses of this type of vaccine than of the killed virus vaccines used to protect against seasonal flu. LAIV are based on weakened viruses that don't cause illness, but they still have to replicate in order to elicit a strong immune response. Viruses with modified haemagglutinin proteins induced strong antibody responses in ferrets in this study, suggesting that vaccines with similar modifications might prove more effective than those tested previously.

"We can't predict how bird flu viruses will evolve in the wild, but the more we understand about the kinds of mutations that will enable them to transmit between humans, the better we can prepare for a possible pandemic," said Professor Barclay.

The research was funded by the Medical Research Council and the Wellcome Trust and published in the Journal of General Virology.


Story Source:

The above story is based on materials provided by Imperial College London. The original article was written by Sam Wong. Note: Materials may be edited for content and length.


Journal Reference:

  1. H. Shelton, K. L. Roberts, E. Molesti, N. Temperton, W. S. Barclay. Mutations in hemagglutinin that affect receptor binding and pH stability increase replication of a PR8 influenza virus with H5 HA in the upper respiratory tract of ferrets and may contribute to transmissibility.. Journal of General Virology, 2013; DOI: 10.1099/vir.0.050526-0

Cite This Page:

Imperial College London. "Bird flu mutation study offers vaccine clue." ScienceDaily. ScienceDaily, 8 April 2013. <www.sciencedaily.com/releases/2013/04/130408085043.htm>.
Imperial College London. (2013, April 8). Bird flu mutation study offers vaccine clue. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2013/04/130408085043.htm
Imperial College London. "Bird flu mutation study offers vaccine clue." ScienceDaily. www.sciencedaily.com/releases/2013/04/130408085043.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Birds Around the World Take Flight

Birds Around the World Take Flight

Reuters - Light News Video Online (Nov. 22, 2014) An imperial eagle equipped with a camera spreads its wings over London. It's just one of the many birds making headlines in this week's "animal roundup". Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins