Fighting Flu (IMAGE) Rockefeller University Caption Antibodies bind to a flu virus protein (grey) with their variable regions (blue) forming an immune complex. The antibodies' Fc region (red) will bind to immune cells. Researchers think flu vaccines could be improved by including immune complexes that contain antibodies with modified Fc regions. Credit Laboratory of Molecular Genetics and Immunology at The Rockefeller University Usage Restrictions Image may only be used to illustrate research described in the accompanying release. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.