Hungarian-born scientist Katalin Kariko's obsession with researching a substance called mRNA to fight disease once cost her a faculty position at a prestigious US university, which dismissed the idea as a dead end.
Now, her pioneering work -- which paved the way for the Pfizer/BioNTech and Moderna Covid-19 vaccines -- has won her the Nobel Prize in Medicine.
Kariko, 68, spent much of the 1990s writing grant applications to fund her research into "messenger ribonucleic acid" -- genetic molecules that tell cells what proteins to make, essential to keeping our bodies alive and healthy.
