The chances of parents ever proving in an English court that their child's autism was caused by the MMR vaccine are about as likely as Tony Blair apologising for the Iraqi war.
Even if they were to get legal aid funding - which has recently been denied to them - they would still have to demonstrate a direct and indisputable causal link.
Chances are better in the American legal system where a federal court is listening to evidence from experts in a test case that could open the floodgates.
The US Court of Federal Claims is considering the tragic case of 12-year-old Michelle Cedillo, who has been wheelchair-bound since being given the MMR vaccine when she was an infant.
The federal court has far less exacting standards of proof than the criminal justice system. Plaintiffs have to establish only that a link between the vaccine and autism is more likely than not.
If the Cedillo case succeeds, there are a further 4,800 similar cases waiting in the wings.
The news has not been so good in the UK, where parents had their final appeal to have legal aid funding re-established turned down. The first appeal was turned down by High Court judge Nigel Davies who revealed only recently that his brother was a director of GlaxoSmithKline, a manufacturer of the MMR vaccine.
The latest appeal was heard by Mr Justice Keith, who confirmed Judge Davies's decision.
The legal aid system had paid out $15m pounds towards the class action suit that was being mounted by 2,000 parents of autistic children - and the case didn't even get close to a courtroom.
(Sources: British Medical Journal, 2007; 334: 1241; USA Today, 11 June 2007).