A Tunisian man carries a sheep suffering from peste des petits ruminants (PPR), also known as sheep and goat plague, a highly contagious animal disease affecting small ruminants. Once introduced, the virus can infect up to 90% of an animal heard and the disease kills anywhere from 30 to 70% of infected animals (photo credit: AgriMaroc [Marrakech]–DR).

Vaccines can lose their potency and become ineffective when being stored or transported. This problem adds to the cost of vaccines and limits their availability. What’s needed, particularly in tropical regions with poor infrastructure and hot and variable climates, are vaccines that can withstand storage or shipment at changing and/or high temperatures.

Keeping vaccines in a narrow band of acceptable temperatures during shipment is challenging and expensive—the ‘cold chain’ consumes about 80 percent of the total cost of vaccination programs according to the U.S. National Sciences Foundation (NSF). . . .

The World Health…