Well the HIV epidemic was caused by a faulty hepatitis vaccine cunningly foisted on the homosexual community in San Francisco in the 70's. So they've dicked around with Hepatitis strains back in the early 1970's and probably a fair bit earlier.

Never underestimate these cunts in bio-labs screwing around with thing they have little understanding. There is a history of fuck-ups and ignorance and shear unabashed negligence.