New Bird Flu Vaccine is 100 Percent Effective in Tests

A team of medical researchers in Pennsylvania have produced a new bird flu vaccine, made from a genetically engineered human cold virus, which is 100 percent effective in protecting vaccinated animals and birds from the H5N1 avian flu virus.
_{Photo courtesy of João Estêvão A. de Freitas}

The vaccine was produced in record time and could prove to be a powerful tool for public health officials if the H5N1 bird flu virus mutates and threatens to become a worldwide pandemic. According to the World Health Organization, 152 humans have contracted the bird flu virus and more than 80 have died.

Producing conventional flu vaccines requires months of work using fertilized chicken eggs to incubate the virus that forms the basis of the vaccine. Researchers at the University of Pittsburgh Medical Center prepared their vaccine in 36 days, grew it in a laboratory dish, and based it on genetic sequence data they received in an e-mail from scientists at the Centers for Disease Control and Prevention.

New Vaccine Based on Human Cold Virus
Essentially, the team artificially generated the DNA coding for a gene that controls a protein found on the surface of all flu viruses, and then spliced the artificial DNA into a human cold virus.

"We have the technique to go from an e-mail to a virus," said Dr. Andrea Gambotto, who led the research team at the University of Pittsburgh, in an interview with CNN. "We generated the portion that we think was important for immunity. We never manipulated the actual H5N1 virus ourselves, so it is safe to generate this kind of vaccine."

Researchers tested the vaccine on mice and chickens, and found that it provided partial protection against the H5N1 virus when administered nasally and 100 percent protection when injected. Gambotto said he expects the vaccine to be just as effective in humans as in animals, because it is based on a human cold virus.

Vaccine Expected to be Effective Against Mutating Virus
According to Gambotto, the vaccine also produced a dual immunological response, which means the bodies of the test animals generated two types of immunity: antibodies that neutralized the virus by preventing it from binding with cells; and T-cells, a kind of super immune cell, that attacked the virus directly.

"This means that this recombinant vaccine can stimulate several lines of defense against the H5N1 virus, giving it greater therapeutic value," said microbiologist Simon Barratt-Boyes of the University of Pittsburgh Graduate School of Public Health and a member of the team, in an interview with the Los Angeles Times. "More importantly, it suggests that even if H5N1 mutates, the vaccine is still likely to be effective against it.”


Gambotto and his team are working with the U.S. Food and Drug Administration to set up human tests of the vaccine, which could begin within a few weeks.

More information:

Breakthrough in bird flu vaccine -- CNN.com

Researchers Make a Bird Flu Vaccine From Human Cold Virus -- Los Angeles Times

Avian Influenza -- World Health Organization