In February 2009, Baxter Biosciences' facility in Orth-an-der-Donau, Austria shipped seasonal H3N2 influenza vaccine contaminated with live H5N1 avian influenza to distributors in the Czech Republic, Slovenia, Germany, and Austria. The contamination was discovered when the Czech distributor Biotest found that 4 of 4 ferrets died after receiving the material. WHO, EMA, and national health agencies investigated. Conspiracy claims that the contamination was a deliberate attempt to seed a pandemic are assessed as not supported; regulators and industry accept accidental contamination of a seed stock as the most plausible explanation.