Jan 3, 2007

Human Tests For Bird Flu Vaccine Begin

Experimental Vaccine Contains DNA Of H5N1 Strain, Promising Flexibility In Addressing Mutations

  •  (AP)

  • Photo Essay Taking Its Toll

    Thailand and Indonesia report new H5N1 bird flu cases in humans and poultry.

  • Special Report Bracing For Bird Flu

    U.S. officials continue to take steps to prepare for and minimize the potential impact of the disease.

(WebMD)  Government scientists say that an experimental vaccine technology could give them a jump on the constantly mutating bird flu virus.

National Institutes of Health (NIH) researchers are in the opening stages of testing on humans a new vaccine against H5N1, the pathogen behind the bird flu outbreak that has sickened at least 261 people since 2003.

The vaccine will also offer a first pass at using experimental DNA technology to make vaccines against flu. Instead of using weakened or killed viruses to prompt immunity in patients, the new vaccine uses chunks of the genetic material of the flu virus to get the body to react and hopefully form a defense against infection. The vaccine does not contain any infectious material and cannot cause infection.

Indonesia Strain

The vaccine, due to be tested by NIH in 45 people, includes DNA from the "Indonesia" strains of H5N1.

At least 55 people contracted bird flu in Indonesia in 2006, more than three times the number in any other country, according to the World Health Organization. Forty-five of those people died.

"That is a hotbed of activity in terms of the virus persisting in animals and transferring to people. That's clearly one of the strains we're concerned about," says Gary Nabel, M.D., director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases.

Currently, flu vaccines must be grown in hen eggs, a process that can take six months or longer to complete. But DNA vaccines can be produced in up to half the time, Nabel says.

DNA vaccines have the potential to allow for the rapid manufacture of vaccine, says Gigi Kwik Gronvall, Ph.D., an immunologist at the Center for Biosecurity at the University of Pittsburgh.

The technology — at least in principle — allows scientists to begin producing vaccine within days of identifying a dangerous disease strain.

"If it works, it would have huge advantages because you could modify your vaccine. That's the dream: to be able to respond to emerging disease quickly," she tells WebMD.

A Lot Of 'Ifs'

But scientists must first find out if the DNA vaccine works in humans. Two-thirds of the 45 patients in NIH's study will be given an active form of the vaccine to test it for safety and to see if it reliably prompts an immune response.

Finding out whether it can actually prevent infection with real-world H5N1 virus would be the next step.

"There are a lot of 'ifs' here," Gronvall says.

DNA vaccines against the human immunodeficiency virus (HIV) have already shown some ability to prompt immune responses in the short term.

"We really don't know if DNA vaccines will work for flu," Nabel says.



SOURCES: Epidemic and Pandemic Alert and Response (EPR), World Health Organization, Dec. 27, 2006. Gary Nabel, M.D., director, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health. Gigi Kwik Gronvall, assistant professor of immunology, University of Pittsburgh School of Medicine, Center for Biosecurity.



By Todd Zwillich
Reviewed by Louise Chang
Copyright 2007, WebMD Inc. All rights reserved.
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Add a Comment
by bluestardad January 5, 2007 10:41 AM EST
Medical Field; Cure anything then get back to me. Prove to America you are worth the billions we spend on you. Quit pulling out the boogy man and trying to scare America with your bird flu bologna.
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by drinuk January 4, 2007 4:09 PM EST
I would'nt touch it with a bargepole, yet another big scare story to get the stock prices up for Big Pharma. There ain't no rampant infection from birds, it is a scam.

Why don't they put as much effort into the KNOWN cures for cancer instead of encouraging the FDA to jail those selling natural cures they cannot patent !!!
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