While it is difficult to deal directly with vaccines and test their stability, many heat-labile enzymes might serve as models. While this enzyme is common classroom experimental material, it is interesting that some important aspects of it are not subsequently studied. During one's survey of where it is found in nature, one should keep note of which organisms where it is NOT found. Then one should tie this in with why an organism would need catalase in the first place. Effect of various antibiotics on Lac-Operon induction.
Gene expression is a common classroom topic.
Selected antibiotics inhibit various steps in the gene expression pathway. This can then be correlated with the clotting of blood with and without the addition of these same antibiotics.