![]() Ongoing cold chain monitoring is an integral part of immunization practices. Products that have been exposed to adverse environmental conditions should be managed in accordance with specific instructions from public health officials or the vaccine supplier. Data are available to indicate that some products remain stable at temperatures outside of the recommended range for specified periods of time, but mechanisms rarely exist for monitoring the effect of cumulative exposures. ![]() It can be difficult to assess the potency of a mishandled vaccine because there is little information about vaccine degradation multipoint stability studies on vaccines are challenging to perform and information from manufacturers is not always available. Freezing of a vaccine or diluent may cause cracks in the container which may lead to contamination of the contents. Some vaccines, such as those containing an aluminum adjuvant, experience a permanent loss of potency due to adjuvant clustering when subjected to freezing and thawing. Repetitive exposure to increased temperature can result in protein denaturation and a cumulative loss of potency that is not reversible. Vaccines exposed to temperatures above the recommended temperature range may experience some loss of potency with each episode of exposure. There are several negative consequences of breaks in the cold chain. Refer to the list of steps in handling vaccines exposed to inappropriate vaccine storage conditions for product specific storage recommendations. ![]() Exposure of a vaccine to environmental conditions outside those recommended for the product is called a cold chain break, breach or failure, or temperature excursion. Monitoring of vaccines' cold chain is required to ensure that these products have been stored and transported at recommended temperatures and in correct conditions. "Cold chain" refers to the process used to maintain optimal conditions, particularly temperature, during the transport, storage and handling of vaccines, beginning at the manufacturer and ending with administration of the vaccine to the vaccine recipient. Recommendations for vaccine storage and handling procedures may vary across jurisdictions, and if additional information is required, it is advised to consult your jurisdictional/local public health office or immunization program. Detailed information for vaccine providers regarding vaccine storage and handling is available in the Public Health Agency of Canada's (PHAC) National Vaccine Storage and Handling Guidelines for Immunization Providers (2015). The recommendation for revaccination of people who have received a potentially ineffective immunizing agent may cause a loss of public confidence in vaccines and the health care system, as well as inconvenience for the vaccine recipient and the provider.Ī detailed discussion of storage and handling recommendations for immunizing agents is beyond the scope of the Canadian Immunization Guide. ![]() Loss of immunizing agents may result in the cancellation of immunization clinics, resulting in lost opportunities to immunize, as well as increased costs to the program. Losses of immunizing agents are expensive and may exacerbate existing supply problems.Administration of a compromising immunizing agent may result in the occurrence and possible transmission of a vaccine preventable disease. There is a need to ensure that an effective product is being used.Maintaining the potency of immunizing agents is important for several reasons: Conditions that result in loss of potency vary among products. Loss of potency can be accelerated under certain conditions of transport, storage and handling and may result in failure to stimulate an adequate immunologic response, leading to lower levels of protection against disease. Immunizing agents are biologic materials that are subject to gradual loss of potency from deterioration and denaturation.
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