Opportunities and challenges of developing thermostable vaccines.

All vaccines lose potency over time and the rate of potency loss is temperature-dependent. Therefore, cold-chain systems have been established to ensure that the potency of vaccines is maintained by storing them under refrigerated conditions (in most cases between 2 and 8 degrees C) until the point of use. This article aims to review the approaches being used to develop thermostable vaccine formulations that would be resistant to damage caused by freezing or excessive heat, and that could reduce dependence on the cold chain. The challenges associated with the implementation of these novel formulations are discussed, as well as the potential benefits and opportunities of taking vaccines out of the cold chain.