H1N1 Virus (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption A mutation in the H1N1 influenza A virus -- a pair of amino acid variants termed the "SR polymorphism" -- was found to enhance replication of the virus in humans. Credit Image courtesy of NIGMS Usage Restrictions None 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.