SV40's an abbreviation for Simian vacuolating virus 40 or Simian virus 40, a polyomavirus that's found in both monkeys and humans. Like other polyomaviruses, SV40's a DNA virus that's the potential to cause tumors, but most often persists as a latent infection. History The virus was first identified in 1960 in cultures of rhesus monkey kidney cells that were being used to produce polio vaccine. It was named for the effect it produced on infected green monkey cells, which developed an unusual nu… (More on Sv40)