Bird-flu vaccine works at high doses; Focus turns to ways to stretch vacc...( time. The dose most effective in ...),Health

The dose most effective in the NEJM study would be difficult to produce, using conventional manufacturing methods, for a significant portion of the world's population. So researchers are turning their attention to ways to stretch the vaccine.

In one approach taking place at Rochester and several other sites, 1,200 people are taking part in a study of the vaccine together with an adjuvant, a substance designed to enhance the response of the immune system. The vaccine will be given with alum, a vaccine additive that has been used in commercial vaccines for decades to make them more effective, in two studies involving 600 participants each. If alum is effective, researchers ultimately would be able to reduce the amount of vaccine given to each person, thus making the vaccine available to more people.

The studies are sponsored by the National Institute of Allergy and Infectious Disease, the Federal agency leading the effort to create a vaccine against bird flu. NIAID is currently testing the vaccine in people 65 and older and in young children. It's also sponsoring studies looking at ways to speed the vaccine manufacturing process, and at new ways to deliver the vaccine, as officials work to head off a potential pandemic of bird flu. The disease has claimed the lives of more than half the people it has infected.

"These findings represent an important step forward in the nation's efforts to prepare for the possible emergence of a human pandemic of H5N1 avian influenza," noted NIAID Director Anthony S. Fauci, M.D. "We are working hard to address the many challenges that remain with regard to the development of an H5N1 vaccine."

In some ways the high doses necessary to create an immune response are not surprising. In a previous study of an experimental bird flu vaccine led by Treanor, conducted in 1998 when bird flu was killing chickens at an alarming rate in Hong Kong, two shots of 90 micrograms each were needed to produce pro
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Contact: Tom Rickey
tom_rickey@urmc.rochester.edu
585-275-7954
University of Rochester Medical Center
29-Mar-2006