Temperature Sensitivity of the Diphtheria Containing Vaccines
Immunization managers can improve the efficiency of immunization programmes through enhancing their knowledge of a vaccine’s stability.
Vaccine management is basically all the actions related to handling of vaccines at the country level from the moment they arrive until the moment they are used. These include arrival and acceptance procedures, appropriate temperature monitoring, ensuring sufficient storage volume, maintaining standards of buildings, equipment and vehicles, effective stock management, vaccine delivery systems as well as effective use of policies such as the multidose vial policy (MDVP) and the use of vaccine vial monitors (VVM).
The World Health Organization (WHO) and UNICEF offer standard tools to effectively monitor management performance of vaccine stores and the vaccine management system in a country (World Health Organization, 2010).
Assessments conducted in various countries on effective vaccine management (EVM) indicate that maintaining equipment at the temperature range recommended by the WHO is not always observed (Milstien J et al., 2006). Moreover, in case of such violations, no proper follow-up actions are taken. Many countries still lack appropriate temperature monitoring tools for vaccine stores and refrigerators. Among the studies documenting temperature violations there are some that indicate that temperature violations may affect the diphtheria containing vaccines (Bishai et al., 1992; Burgess & McIntyre, 1999; Hanjeet et al., 1996; Lugosi & Battersby, 1990; Jeremijenko et al., 1996; Milhomme, 1993; Thakker & Woods, 1992; Wawryk et al., 1997; Wirkas et al., 2006). It has been observed that cold chain practices tend to rather prioritize protecting vaccine from heat damage, thus often creating the risk of exposure to freezing temperatures. As a result, inadvertent freezing of vaccines is a largely overlooked problem all over the world. In a recent systematic review, comparison of the occurrence of freezing temperatures during storage and transport were found to be a global problem occurring both in the resource-rich as well as the resource-limited settings (Matthias et al., 2007).
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