Scientists have identified the structure of a key protein behind a common respiratory virus, a finding that may provide a potential target for vaccines or treatments for the illness.Respiratory syncytial virus (RSV) is a very common virus that leads to mild, cold-like symptoms in adults and older healthy children. In the study, the researchers mapped the molecular structure of an RSV protein known as NS1. As the protein was unknown yet, scientists were unable to determine exactly how NS1 interfered with the immune system.Knowing the structure of the protein will help them understand how the virus impedes the immune response, potentially leading to a vaccine or treatment for this common infection, the researchers said.By suppressing the immune response, the virus gives itself a better chance of surviving and multiplying, or in other words, of causing disease. "Now that we have the structure, we're able to see what the protein looks like, which will help us define what it does and how it does it. And that could lead, down the road, to new targets for vaccine or drug development," said Daisy Leung, assistant professor at Washington University in St. Louis in a paper published in the journal Nature Microbiology.