How can we be sure that someone on the other side of the apparatus won't use their position as a means towards necessary training and equipment, and as an oppor

How can we be sure that someone on the other side of the apparatus won't use their position as a means towards necessary training and equipment, and as an opportunity to act with authority above suspicion, to engineer this supposed killer virus that destroys us all? What if they become the problem we tasked them with preventing?