Though we ice pack and insulate all orders for parvovirus and other dog vaccines, it is possible you find the ice packs thawed or even warm when you receive them. Ice packs and insulation will do the job of providing you with viable canine vaccines under normal shipping of 3 to 4 days. Unless subjected to extreme heat, the parvovirus and other dog vaccines will be fresh. Be sure to refrigerate the dog vaccines as soon as you receive them.