Featured Research

from universities, journals, and other organizations

Studies showing how bird flu viruses could adapt to humans offer surveillance and vaccine strategies

Date:
June 6, 2013
Source:
Cell Press
Summary:
Bird flu viruses are potentially highly lethal and pose a global threat, but relatively little is known about why certain strains spread more easily to humans than others. Two studies identify mutations that increase the infectivity of H5N1 and H7N9 viruses through improved binding to receptors in the human respiratory tract. The findings offer much-needed strategies for monitoring the emergence of dangerous bird flu strains capable of infecting humans and for developing more effective vaccines.

Bird flu viruses are potentially highly lethal and pose a global threat, but relatively little is known about why certain strains spread more easily to humans than others. Two studies published by Cell Press June 6th in the journal Cell identify mutations that increase the infectivity of H5N1 and H7N9 viruses through improved binding to receptors in the human respiratory tract. The findings offer much-needed strategies for monitoring the emergence of dangerous bird flu strains capable of infecting humans and for developing more effective vaccines.

"Avian influenza viruses evolve rapidly, and there are many subtypes of these viruses that we need to be concerned about because, in many cases, humans do not have immunity to these newer strains," says senior study author Ram Sasisekharan of the Singapore-MIT Alliance for Research and Technology. "Our findings can be put to use to monitor the evolution of H5N1 and H7N9 viruses in the field as well as in the clinic if and when there is an outbreak."

In the past 10 years, the H5N1 virus has infected nearly 600 individuals in several outbreaks around the world, killing about 60% of those infected. And over the past few months, a lethal subtype of the H7N9 virus has been found in at least 131 people, mostly in mainland China. Although these viruses do not normally infect humans, over time they can adapt to humans and gain the ability to spread more easily from person to person, underscoring the importance of finding out which mutations could enhance the ability of these viruses to infect humans.

To address this question, Sasisekharan and his team analyzed the structure of the H5N1 and H7N9 viruses, focusing on hemagglutinin (HA) -- a type of viral protein that binds to cell receptors in the respiratory tract of hosts. They characterized the set of HA mutations required to increase the preference of the viruses for human receptors, discovering that only a single amino acid change in the HA sequence is necessary for this to occur. Moreover, they found that distinct HA mutations are evolving in the H7N9 virus indicating that currently recommended H7 vaccines would not be effective against this newly emerged virus.

"Right now, there is no vaccine to protect against the H7N9 virus, and our findings could guide efforts to develop effective vaccine strategies," Sasisekharan says.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal References:

  1. Kannan Tharakaraman, Akila Jayaraman, Rahul Raman, Karthik Viswanathan, NathanW. Stebbins, David Johnson, Zachary Shriver, V. Sasisekharan, Ram Sasisekharan. Glycan Receptor Binding of the Influenza A Virus H7N9 Hemagglutinin. Cell, 2013; DOI: 10.1016/j.cell.2013.05.034
  2. Kannan Tharakaraman, Rahul Raman, Karthik Viswanathan, NathanW. Stebbins, Akila Jayaraman, Arvind Krishnan, V. Sasisekharan, Ram Sasisekharan. Structural Determinants for Naturally Evolving H5N1 Hemagglutinin to Switch Its Receptor Specificity. Cell, 2013; DOI: 10.1016/j.cell.2013.05.035

Cite This Page:

Cell Press. "Studies showing how bird flu viruses could adapt to humans offer surveillance and vaccine strategies." ScienceDaily. ScienceDaily, 6 June 2013. <www.sciencedaily.com/releases/2013/06/130606140616.htm>.
Cell Press. (2013, June 6). Studies showing how bird flu viruses could adapt to humans offer surveillance and vaccine strategies. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/06/130606140616.htm
Cell Press. "Studies showing how bird flu viruses could adapt to humans offer surveillance and vaccine strategies." ScienceDaily. www.sciencedaily.com/releases/2013/06/130606140616.htm (accessed April 23, 2014).

Share This



More Plants & Animals News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Monkeys Are Better At Math Than We Thought, Study Shows

Monkeys Are Better At Math Than We Thought, Study Shows

Newsy (Apr. 23, 2014) A Harvard University study suggests monkeys can use symbols to perform basic math calculations. Video provided by Newsy
Powered by NewsLook.com
Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. 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:
from the past week

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