 The Homeland Security Act of 2002 provides another exception to the exclusive jurisdiction of the vaccine court.If smallpox vaccine were to be widely administered by public health authorities in response to a terrorist or other biological warfare attack, persons administering or producing the vaccine would be deemed federal employees and claims would be subject to the Federal Tort Claims Act, in which case claimants would sue the U.S. Government in the U.S. district courts, and would have the burden of proving the defendants' negligence, a much more difficult standard.In the vaccine court, as in civil tort cases, the burden of proof is a preponderance of evidence, but while in tort cases, this is met by expert testimony establishing a rigorous scientific case, in the vaccine court, the burden is met with a three prong test