The study provides data about the antibody attachment site that are similar to the findings of another research group, reported on February 22, 2009 (see http://www3.niaid.nih.gov/news/newsreleases/2009/flu_mab.htm). Taken together, these studies provide a blueprint for efforts to develop new antiviral drugs as well as a potential universal influenza vaccine.
The Scripps research team, led by Ian A. Wilson, Ph.D., in collaboration with researchers at the biopharmaceutical company Crucell Holland (The Netherlands), discovered the potent antibody during a systematic examination of blood samples taken from healthy individuals who previously had been vaccinated with the ordinary seasonal flu vaccine. Using sophisticated screening technologies, the scientific team isolated antibodies that recognise flu viruses to which the average person has never been exposed, such as H5N1 avian flu viruses. Through this process, the scientists found one antibody called CR6261 that had broad neutralising capabilities. Subsequently, they found several antibodies similar to CR6261 in other donors as well. With the help of a robotic crystallisation laboratory, the Scripps team quickly determined the detailed three-dimensional structures of this antibody when bound to the H1 virus that caused the 1918 pandemic flu as well as to an H5 virus with pandemic potential. CR6261 bound to a relatively hidden part in the stem below the mushroom-shaped head of the haemagglutinin protein, one of two major surface proteins found on the flu virus.