A new computerized method of testing could help world health officials better identify flu vaccines that are effective against multiple strains of the disease.
Rice University scientists who created the method say tests of data from bird flu and seasonal flu outbreaks suggest their method can better gauge the efficacy of proposed vaccines than can tests used today.
Rice's Michael Deem, the lead scientist on the project, will present the group's results March 19 at the American Physical Society's 2009 meeting in Pittsburgh. The results are also slated to appear in the forthcoming book "Influenza: Molecular Virology" from Horizon Scientific Press.
Avian flu, or bird flu, is a particularly deadly type of flu that's transmitted from birds to humans. It hasn't yet evolved into a form that can be transmitted readily between humans, but scientists and world health authorities are trying to prepare for a potential outbreak. Because the virus mutates continually, creating a vaccine in advance is problematic. For example, scientists have already found that a vaccine designed for the 1997 strain of bird flu does not work against a 2003 strain.
"Current vaccines contain only a single version of a given flu subtype," Deem said. "We wanted to gauge the effectiveness of a vaccine that contained multiple versions of a given subtype."
World health authorities currently test the efficacy of proposed flu vaccines using either ferrets, which can contract the same forms of flu as people, or genetic assays. Rice's new computerized method could be a cheaper and faster alternative.
With the new method, flu virus mutations are assigned numerical scores. Deem, Rice's John W. Cox Professor of Bioengineering and professor of physics and astronomy, and colleagues developed the method so they could assign a number that captured the amount of difference or similarity between strains. The method can also be used to test how effective a vaccine will be against divergent strains. To verify this, the team checked their results against flu vaccine data collected by the World Health Organization from 1971 to 2004.