Evaluation of the cold chain encountered by6 wet' 1-2 Newcastle disease vaccine from the vaccine production department to the village chicken in Mozambique

摘要

Live vaccines are biological products that must be stored away from excess heat, cold or light to ensure maximum potency. The only way to ensure the appropriate conditions for vaccine storage and transport is to have a functional and validated cold chain. However, in developing countries such as Mozambique, maintenance of the cold chain and conservation of vaccines present many challenges. 1-2 Newcastle disease (ND) vaccine is ideal for such situations since it can be stored outside refrigeration forshort periods, using simple methods that are within the resources of community vaccinators. The vaccine cold chain encountered by 'wet' 1-2 ND vaccine in Mozambique was described and evaluated using data loggers. It was found that the cold chain is composed of four major stages, namely 1. Veterinary Research National Institute in Maputo, 2. storage at the Provincial Livestock Services, 3. District Directorate of Agriculture and 4. community vaccinator. The vaccine cold chain in Mozambique can be divided into the 'conventional cold chain' and the 'non-conventional' cold chain. The temperatures in the 'conventional cold chain' (refrigerators and cold rooms, domestic refrigerators, and insulated boxes with icepacks used for distribution of vaccine) weresometimes outside the recommended range of 2-8 °C. The main factors responsible for this were the poor handling and monitoring procedures, and inappropriate equipment. The temperatures in the 'non-conventional cold chain' (storage of vaccine in a cool place in the home of the community vaccinator, and transport wrapped in a damp cloth in an open-weave basket during vaccination) were below 29 °C, except where synthetic bags were used for vaccine transport.