By Sean Henahan, Access Excellence

The results of  a 10-site study conducted under the auspices of  the National Institute of Allergic and Infectious Diseases (NIAID) showed the vaccine to be safe and well tolerated. Even more important, it seems to work.  Overall, the attenuated live-virus vaccine provided 93 percent protection against influenza in this population. Only one percent of 1,070 children who received the vaccine developed culture-confirmed influenza during last year's flu season versus 18 percent of 532 children the same age who received placebo.

"The initial results from this trial are very exciting," comments Anthony S. Fauci, M.D., director of NIAID. "An influenza vaccine given in a nasal spray would be easier to administer and more acceptable than an injection, especially to children. Such a vaccine could have a significant impact on public health."

Caption: Electron Micrograph of Influenza (CDC)

"The clinical trials demonstrate that the vaccine is safe, immunogenic, genetically stable and highly effective. It is very gratifying to see our years of effort pay off this way," said vaccine pioneer Dr. Hunein Maassab, professor of epidemiology at the University of Michigan School of Public Health, who has been working on the vaccine since 1973.

The intranasal form of the vaccine was designed to do more than spare people the pain of the typical vaccine jab. The vaccine triggers an early, local antibody response in the nasal passages---a powerful first line of defense and a key element in the prevention of influenza. This represents a new approach in immunization. School age children are major carriers of the disease. Influenza kills 20,000 people each year in the United States alone.

"This is a tremendous accomplishment," said Noreen M. Clark, dean of the University of Michigan School of Public Health. "The results of the clinical trials are the successful culmination of three decades of dedication and innovation by Dr.Maassab and his research team. The vaccine is likely to have a major impact on U.S. public health in the future."

The new vaccine uses weakened and harmless or "attenuated" live viruses that produce stronger and longer lasting immunity than that produced with the traditional dead virus vaccine. The tri-valent vaccine contains two different A influenza strains and one B strain, and protected children from both the A and B strains circulating last year, Maassab said.

The vaccine, which combines the core of the harmless influenza virus with the covering from a virulent strain, is highly adaptable. The core virus can be stored until a flu epidemic breaks out and then 'retrofitted' with an outer covering that matches the virus causing the epidemic, Maassab explained.

FDA approval of the new vaccine is expected within one year. The trail results were announced July 14, 1997 by the National Institute of Allergic and Infectious Diseases (NIAID)