In an opinion that could significantly lower the threshold for proof of general causation in product liability lawsuits if adopted elsewhere, on June 21, 2017, the European Court of Justice held that a court could find a vaccine “defective” and thus the cause of a disease, even where no medical research supported such a causal relationship. Instead, the causal relationship could be established by mere evidence of a previous excellent state of health, lack of any family history of the disease, a close temporal connection between the vaccination and appearance the disease of multiple sclerosis, and a significant number of reported cases of the disease occurring following administration of the vaccine. The vaccine in issue was to inoculate against hepatitis B, and the allegation was that the vaccine caused multiple sclerosis.
It has been the law in the European Union that a producer of a product, such as a vaccine, is liable for a defect in its product if the injured person can prove damage, a defect, and a causal relationship between the defect and damage. During the appeal of this case, the French courts had struggled with the causal relationship evidence because there was no scientific consensus supporting a relationship between the vaccination and multiple sclerosis, because all national and health authorities had rejected such an association, and because 92 to 95% of persons with multiple sclerosis have no family history of the disease.
Despite these undisputed facts, the EU Court nonetheless found that the lower court could rule the vaccine defective and caused multiple sclerosis. In so ruling, and in a case of the tail wagging the dog, the Court emphasized that:
- Excluding any method of proof other than medical research could make it excessively difficult, if not impossible, to establish producer liability in many situations.
- It still required that the non-scientific evidence of the causal relationship between the defect and the disease should be “sufficiently serious, specific and consistent to warrant the conclusion” that the vaccine’s defect is “the most plausible explanation for the occurrence of the damage.”
While the United States and Europe have very different regulatory schemes, any dilution of causation proof may have serious implications for products liability, especially as global organizations increasingly collaborate and as the US and EU trade regulatory, pharmacovigilance and even legal concepts. Further, while the issue before the Court involved liability of vaccine manufacturers, the ability to use “serious,” “specific” “consistent” and “most plausible” evidence rather than medical research to establish producer liability could easily have implications beyond the vaccine industry. A statement regarding the Court’s ruling is available here.