Ok, first let me be very clear: I am firmly convinced that all vaccines are greatly over used, and even when they are used correctly, they might not be the best choice. That said, here is a link to a story about a British student who has perfected a means of maintaining vaccines at the ideal temperature while in transit, that works for up to 30 DAYS.
What gets my attention is the possibility that the same tech can be used for transporting organ transplants, camping foods, and a lot more.