If my kids gave rsv virus to their grandfather can they catch it back from him? hes had symptoms for a week and both the kids appear to be ok now. they are suppose to go to his house today but i dont want them to get the virus back.

No: RSV is one of many "cold" viruses that accounts for a majority of URI's in season. Once a kid develops that infection & their body heals, they are immune for at least that season though the immunity will eventually fade. You don't pass RSV back & forth like a strep throat. They could get another "cold" this season but from a different virus.