Malaria is more akin to an exploit than a vulnerability.
However, if we are to persist with your example, what you are trying to say is more akin to "Studying malaria and developing, or buying, a genetically engineered infectious disease that uses malaria's infection vector, and stockpiling it in a warehouse, and sometimes secretly using it, and not telling anyone about this isn't making people any sicker."
However, if we are to persist with your example, what you are trying to say is more akin to "Studying malaria and developing, or buying, a genetically engineered infectious disease that uses malaria's infection vector, and stockpiling it in a warehouse, and sometimes secretly using it, and not telling anyone about this isn't making people any sicker."