Thought I would send this because of the current discussion. This actually has 
been reported quite a bit. No one has suffered any consequences dispite all the 
uproar about peanut butter, etc. Contamination of vaccine with live, 
transmissible Avian Flu virus has been reported. The vaccine was shipped to 
something like a dozen countries for use. Fortunately it was caught. On the 
other hand, Bayer Corp. had vaccine with Aids contamination which was 
distributed and apparently used in various counties overseas. No one has been 
held responsible for either of these occurances. In the case of the Flu vaccine 
contamination it appears unreasonable that it was a mistake.
Paula

 
http://www.congresscheck.com/2009/03/05/%e2%80%98accidental%e2%80%99-contamination-of-vaccine-with-live-avian-flu-virus-virtually-impossible/