Is it easier to create a vaccine for a disease when you know it’s original source?

Question: Is it easier to create a vaccine for a disease when you know it’s original source?
- Keywords:
  disease,
  origin,
  vaccine
Asked by anon-256591 on 9 Jun 2020.
- Alena Pance answered on 9 Jun 2020:
  
  Hi Diego,
  
  Understanding the path a pathogen has followed certainly helps, because with the technology we have now, we can analyse if and how much it changes as it expands from one place to others. This knowledge helps to find molecules of the pathogen that are conserved among the various versions or strains of the pathogen in geographically different places and that doesn’t vary too much.
  The proteins (gene products) that are important for the pathogen, can be under huge evolutionary pressure so they tend to mutate (change) quite a lot and this is not good for a vaccine target because it means the vaccine will not be effective throughout time. The best example is influenza, the virus that causes flu. It mutates a lot and as a consequence the vaccine that worked last year won’t work against the version of the virus going around this year.
  So though knowing the source of the pathogen won’t directly contribute to making a vaccine, it will give important information for the design of a good one.

Question: Is it easier to create a vaccine for a disease when you know it’s original source?