Vacuum Packaging Foods can increase the shelf life of some foods, but it is NOT a food preservation method by itself. If the food required refrigeration or freezing before vacuum selaing, it must still be kept refrigerated or frozen. In fact, vacuum packaging will increase the ability of the botulism bacteria to grow by removing oxygen. Essentially, vacuum packaging removes oxygen that would otherwise be left to influence spoilage of foods, such as rancidity.
NCHFP Resource. Vacuum packaging foods.