CDC Schematic of influenza virus (IMAGE) Duke University Caption A schematic diagram of the influenza virus, showing the surface proteins hemagglutinin (blue, peanut shaped) and neuraminidase (red, flower shaped), to which antibodies attach during an immune response. A new vaccine from Duke helps the immune system target the stalk of the hemagglutinin protein, rather than its top. Credit U.S. Centers for Disease Control Usage Restrictions No restrictions. License Public Domain 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.