July 11, 2012

H5N1 Virus Could Evolve Quickly

Connie K. Ho for - Your Universe Online

“Knowledge is power.” Sir Francis Bacon, an English author and philosopher once spoke these words. With this theme in mind, the results from a research project on a pandemic strain of the H5N1 bird flu virus were recently published in Science. Scientists were interested in studying how the changes in the H5N1 virus can spread among people through the air by people´s coughs and sneezes.

In the study, researchers genetically modified the H5N1 virus and found that mutations at five locations could cause the pandemic strain to be produced. The team of researchers was led by Ron Fouchier, professor of molecular virology in the department of virology at the Erasmus Medical Center in the Netherlands. They developed an altered version of the H5N1 virus and infected ferrets to see how the virus would travel among animals.

"Our main conclusion is that the H5N1 bird flu virus can acquire the ability of aerosol transmission between mammals, and we show that as little as five mutations, but certainly less than 10, are sufficient to make H5N1 virus airborne," explained Fouchier in an article by the Guardian.

Scientists and biosecurity officials waited eight months to release the data by Fouchier, following a debate on whether the report should be made public. The U.S. government National Science Advisory Board for Biosecurity (NSABB) were concerned that the information could be misused, but scientist argued that the research needed to be published in full so that other investigators and public health authorities could prepare vaccines and public health protocols if a strain of the H5N1 did mutate. Last month, Yoshihiro Kawaoka of the University of Wisconsin, Madison revealed details of another type of the H5N1 virus that can be passed along. He produced a mutated strain of the swine flu virus that appeared in 2009.

Approximately 16 years ago, scientists first identified the bird flu and determined that it can lead to serious illness or death. Even though it cannot spread between humans presently, scientists wanted to understand how many changes were needed before the virus could become airborne. They initially theorized that flu viruses needed to mix with another virus to become pandemic. Fouchier´s projected showed that the “reassortment” process was not needed for the H5N1 virus to become airborne.

An accompanying study featured in Science focused on using computer and mathematical models to better understand if the types of viruses produced by Fouchier and Kawaoka could happen naturally. Derek Smith, professor of infectious diseases at Cambridge University, completed the study. Smith´s team analyzed surveillance data on avian H5N1 viruses over the past 15 years and discovered that two of the necessary five mutations have already been seen in strains that already exist.

"We now know that we're living on a fault line," noted Smith in the Guardian article. "What we have discovered in this working collaboration with Drs. Fouchier and Kawaoka is that it's an active fault line."

With the studies by Fouchier and Kawaoka published, some believe that the publication of the information has more advantages than disadvantages.

"When you get out something into the general literature, you stimulate thoughts and input from people who at first glance you may not think would have an interest in it. So when it's out there in the general literature, anyone from x-ray crystallographers to structural biologists to physiologists to viral epidemiologists can get involved," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, told the Guardian.