19.02.10
New method makes vaccines stable at tropical temperatures
Oxford – A simple and cheap way of making vaccines stable, even at tropical temperatures, has been developed by scientists at Oxford University and Nova Bio-Pharma Technologies. The partnership demonstrated the storage of two different virus-based vaccines on sugar-stabilised membranes for 4 months at 45°C without any degradation. The vaccines could be kept for a year and more at 37°C with only tiny losses in the amount of viral vaccine re-obtained from the membrane. Preparing vaccines that do not need refrigeration has been identified as one of the major unsolved problems in global health. The team's method involves mixing the vaccine with the sugars trehalose and sucrose. The mixture is then left to slowly dry out on a simple filter or membrane. As it dries and the water evaporates, the vaccine mixture turns into a syrup which then fully solidifies on the membrane. The thin sugary film that forms on the membrane preserves the active part of the vaccine in a type of glass, protected from degradation even at high temperatures. Flushing the membrane with water rehydrates the vaccine from the membrane in an instant. According to Nova Bio-Pharma Technologies, the process is general and could be used for many types of vaccines and sensitive biological agents.