Crux of Chicken Vaccines Combine to Produce Deadly Virus by Kai Kupferschmidt:

  • In 2008 two new strains of a deadly chicken virus appeared in Australia, two years after the country introduced a new vaccine in addition to the older two used there.
  • “when the researchers sequenced the genomes of the two new strains and the three vaccine strains, they found that the new viruses were actually stitched together from the European and Australian vaccines.”
  • It seems that somehow two vaccine viruses got into a single animal and recombined in a way that deleted the genes that made them harmless, thus creating a new deadly virus.