Bkmk
Three part X Files beginning with Paper Clip (the real life post WWII secret operation including getting Werner von Braun to work for the US instead of the USSR). Real history: "In November 1945, Operation Overcast was renamed Operation Paperclip by Ordnance Corps officers, who would attach a paperclip to the folders of those rocket experts whom they wished to employ in the United States."
Back to TV series: "Mulder and Scully find a large complex of filing cabinets containing smallpox vaccination records and tissue samples. After realizing that they're filed chronologically by birth date, Mulder finds Scully's file and also that of his sister. Peeling back the label reveals that it was originally marked with his name."
Everyone who had a vaccination was thus on file and had a sample saved in a vial in a file box in a huge building. For use by the government later.
Back then (1995) there weren't dna companies for genealogy.
And in 1995 dna/rna altering jabs for Covid didn't exist yet.