Tracks of Vaccinia Virus-Infected Cells (IMAGE) University College London Caption This image shows the final tracks of how the infected cells moved. The different colors correspond to the time at which cells were infected. Credit Corina Beerli, UCL Usage Restrictions With credit 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.