To maintain stability and viability, most childhood vaccines must be kept cool - both heat and freezing can ruin them. That means they must be refrigerated at the correct temperature throughout transportation, storage, and delivery. This cold chain is difficult and costly to maintain, especially in developing countries. Dr. Sonenshein and his team are working to create childhood vaccines for diphtheria, tetanus, and pertussis (the DTP combination vaccine), and rotavirus-related diarrhea that can withstand a wide range of temperatures without refrigeration by encapsulating them in harmless bacterial spores that are naturally heat-resistant.
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