Maintaining the cold chain for vaccines.

Cold chain for vaccines a is a system for storing and transporting vaccines at very low temperatures to maintain their effectiveness before use. Because vaccines are sensitive biological substances, their exposition to high temperatures directly affects the quality of vaccines and safety of immunization. The goal of this study was to assess the safety of cold chain for vaccines within the cold chain system in two services of Health Center Novi Sad. Cold Chain Monitors (CCM) and Freeze Watch (FW) indicators were used. A total of 155 (94.5%) Cold Chain Monitors (CCM) and 100 (95.2%) Freeze Watch (FW) indicators were analyzed. Only one CCM showed a breack in cold chain. A total of 3 CCMs indicated risk of vaccine wastage. A total of 9 CCMs were colorized without risk of vaccine wastage. FWs were positive in a high percentage in both services of Health Center Novi Sad. FWs were exposed to low temperatures during transport. Statistically significant differencies in the number of exposed CCMs to high temperatures and the number of exposed FWs to low temperatures were observed in these two services. A statistically significant difference in number of FWs exposed to low temperatures was observed in regard to the period of transport and the period of storage at the vaccination stations. The study shows high level of safety of the cold chain in two services of Health Center Novi Sad Cold Chain Monitor is a reliable indicator of the quality of cold chain for vaccines. Freeze Watch is a reliable indicator of the quality of cold chain during storage of vaccines, but not during their transport.