Flu Chart (image) Princeton University Caption Princeton-based researchers developed a model that revealed that the emerging class of cross-protective, or "universal," vaccines will allow for better flu prevention by limiting the influenza virus' ability to spread and mutate. For the above figure, the researchers simulated the effect of a basic cross-protective vaccine on a flu pandemic based on the proportion of the population that received it. They created three groups based on how much the vaccine reduced their contagiousness: by 25 (red), 50 (blue) and 75 (green) percent, respectively. At its most effective, the vaccine resulted in strong "herd immunity," or a general resistance to the virus despite only a part of the population receiving the vaccine. The percentage of the population infected with influenza dropped to zero even though only 70 percent of the population had vaccine protection. Credit Image by Nimalan Arinaminpathy Usage Restrictions None 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.