Five-Way Vaccine for Horses

My mare is due for her five-way vaccine and the local pet supplies store has been sold out of them. I found it at Jeffers (online) for even less than what the local place here sells it for. When I buy it locally, it's taken from a refrigerated environment. So I'm not sure how they keep it cool though during shipping. I am going to have to place a call and find out before I order it. Does anybody know?