Cold Chain System
Vaccines are sensitive to heat. On exposure to heat their potency is lost. Once a vaccine has lost its potency it cannot be regained, so it is important to maintain cold chain. we shall briefly outline the Cold chain system here.
One of the important components of EPI and UIP is the maintenance of cold chain. The cold chain consists of a series of transportation links during which adequate refrigeration is required to maintain potency of vaccine. All vaccines retain their potency at temperature between + 2 to + 8 degree Celsius. The temperature of refrigerator should be recorded on temperature chart everday. Dial thermometer is used to check temperature of the vaccine. The vaccines should not be frozen or exposed to direct sun light.