Why is it necessary to safely store the pathogens of a disease against which vaccines 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 a 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.