Biggest Thing Since Invention of Vaccines Themselves?

  If a person can build up a natural immunity against a disease, can that be transferred to another person? If so, rather than come up with a vaccine, we would just need to transfer from one person to another the proteins or whatever it is that provides the immunity.

  Not exactly a heart transplant, but you get the idea.

  And, would we need the testing-and-approval process? If you can test people, and verify they have the proteins, then do you not know those proteins will work -- without testing them?

   ARUP Laboratories, a Utah company, has developed testing that shows whether a person has the immunity to COVID-19. No word in the news story that I read saying whether they are looking into transferring the immunity from one person to another, but I wonder.

    I do not know of myself, but wonder if this could be the biggest thing since the invention of vaccines, themselves. I do not even know if you can extract the proteins from one person, that you should even be able to transfer them to another. 

   But, I hope so.

   If it requires blood transfusions, or whatever, I hope it works.
   NOTE ADDED 4/17/20:
   ARUP Laboratories is not the only company working to develop antibody testing. CNN reported testing has been done in at least Santa Clara, Calif.; Telluride, Colo.; and Miami, Fla.
   CNN also reports that it is, indeed, being studied to determine in antibodies can be transferred from one person to another, by blood plasma transfers.  While I suggested this could be the biggest thing since vaccines themselves, the CNN story I heard offered no such fanfare.