I was scared, too. I still get edgy!
From what ds's doctor explained -- almost all kids get RSV at some point in their lives. The key is preventing it when they're very very young when their respiratory systems are still developing. When there's a greater risk of complications. With time, your child is going to start developing some resistance to viruses, so as they get older, the symptoms should be milder. From what I understand RSV = lots of snot and with teeny tiny infants, they can't blow their noses or move that stuff up and out.
When DS was getting his synagis shots, I believe there were a couple of RSV cases at his daycare and around that time he did develop an upper respiratory bug -- was wheezy and coughed on occaison, but at the time didn't develop a fever, wasn't breathing excessively fast (normal). Just increased the CPT when it occured.
Liza