✔The complexity of pathogenesis of hazardous pathogens varies from each one and day to day new pathways,new antigenic components of such pathogens are identified.
✔To face and meet new challenges thrown by these pathogens like which includes mutations in antigenic structures,or opting of this pathogen to new host with an extended host range.
✔They need to be stored safely to study these things or it's potential use in developing biological technologies which may come into play in future which cannot be predicted.