Research Explainer (VIDEO) University of Liverpool This video is under embargo. Please login to access this video. Caption Professor Melita Gordon explains the background and findings of the study 'Nonspecific effects of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a.' Credit Professor Melita Gordon Usage Restrictions credit attributed 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.