why is it necessary to safely store the pathogens of a disease against which vaccine are to be produced?

✔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.