The present invention provides compositions comprising conjugate molecules that are structurally stable at a temperature of between about 2 degrees C. and 8 degrees C. In some examples, a conjugate molecule comprises an antigen, such as an allergen. In some examples, a conjugate molecule comprises the Ragweed antigen Amb a 1. The present invention provides methods for making and using such compositions. Provided herein are methods for modulating an immune response in an individual comprising administration of a composition comprising a structurally stable conjugate molecule as described herein.