The first phase of the avian flu vaccine trial, conducted at various other medical centers around the country, tested the vaccine in normal, healthy adults and determined it was safe to test in other populations.
The development of a widespread epidemic of avian influenza, or "bird flu," is of growing concern throughout the world.
Human cases, with a high fatality rate, have been reported in Vietnam, Thailand and Cambodia. Public health experts fear that avian flu could lead to a worldwide pandemic if the virus becomes easily transmittable, leading to a public health crisis.
Currently, most people are highly vulnerable to infection from avian influenza, as the current influenza vaccines do not protect against this new strain of the virus, making the development of new vaccines against avian flu a major priority.
"We believe in some cases in Asia that the avian flu has been passed from human to human, and we're concerned that the virus will evolve to spread easily among the human population and become a global pandemic," said Edwards, professor of Pediatric Infectious Diseases and vice chair of clinical research in the Department of Pediatrics.
"Developing an effective vaccine is our best defense. The elderly, in particular, could be at high risk for complications and death from infection, so it is very important to test the new vaccine in older adults."
Avian flu first emerged in Hong Kong in 1997 and has spread among poultry populations in some Asian countries. Humans have contracted the virus from sick animals, and evidence has pointed to a small number of cases in which human-to-human transmission is believed to have occurred. Identified as H5N1, the strain of the influenza virus has shown a high mortality rate - approximately 72 percent - with many fatalities among previously healthy young people.
The vaccine researchers are testing was made by Sanofi Pasteur from an inactivated H5N1 avian flu virus isolated last year.
"It's similar to the concept of the regular flu vaccine that people get every year, but it's targeted to this novel type of flu," Edwards said.
Because the study is beginning at the start of this year's influenza season, all participants will be given this year's licensed influenza vaccine if desired. Participants will then be given three doses of either the bird flu or placebo vaccine over the next six months and will be required to provide blood samples to test if protection against the virus was produced.
People 65 years or older who are interested in hearing more about the avian flu vaccine study, may call the Avian Influenza Hotline at 615-322-8740.