Bulletin of the World Health Organization
Print version ISSN 0042-9686
NELSON, Carib M. et al. Hepatitis B vaccine freezing in the Indonesian cold chain: evidence and solutions. Bull World Health Organ [online]. 2004, vol.82, n.2, pp.99-105. ISSN 0042-9686. http://dx.doi.org/10.1590/S0042-96862004000200006.
OBJECTIVES: To document and characterize freezing temperatures in the Indonesian vaccine cold chain and to evaluate the feasibility of changes designed to reduce the occurrence of freezing. METHODS: Data loggers were used to measure temperatures of shipments of hepatitis B vaccine from manufacturer to point of use. Baseline conditions and three intervention phases were monitored. During each of the intervention phases, vaccines were removed progressively from the standard 2-8 °C cold chain. FINDINGS: Freezing temperatures were recorded in 75% of baseline shipments. The highest rates of freezing occurred during transport from province to district, storage in district-level ice-lined refrigerators, and storage in refrigerators in health centres. Interventions reduced freezing, without excessive heat exposure. CONCLUSIONS: Inadvertent freezing of freeze-sensitive vaccines is widespread in Indonesia. Simple strategies exist to reduce freezing - for example, selective transport and storage of vaccines at ambient temperatures. The use of vaccine vial monitors reduces the risk associated with heat-damaged vaccines in these scenarios. Policy changes that allow limited storage of freeze-sensitive vaccines at temperatures >2-8 °C would enable flexible vaccine distribution strategies that could reduce vaccine freezing, reduce costs, and increase capacity.
Keywords : Hepatitis B vaccines; Freezing; Refrigeration; Drug storage [methods]; Transportation; Drug stability; Child health services; Indonesia.