European court vaccine decision – a legal analysis

On June 21, 2017 the European Court of Justice (ECJ) decided a product liability case (N.W. et al v. Sanofi Pasteur MSD SNC, C-621/15) described by news articles as allowing plaintiffs to be compensated for alleged vaccine harms, even when there is no scientific evidence of a causal connection (in the most extreme versions, “with no proof”). This description is incorrect. More nuanced analyses were provided by Orac and Steve Novella, but I think they, too, did not exactly capture what the decision does. This post explains the European court vaccine decision.

Three take-home points are important:

  1. If there is no scientific consensus as to whether a vaccine causes a particular kind of injury, member state courts can allow plaintiffs to use circumstantial evidence to prove a vaccine injured them. Defendants, of course, can use scientific evidence to counter the plaintiff’s circumstantial evidence. This decision does not mean that science doesn’t matter in the courts or that anti vaccine activists can win even when the science is against them.
  2. Member courts cannot treat circumstantial evidence as creating a presumption of causation. The plaintiff bears the burden of proving the vaccine cause the injury, and each case must be examined on its facts.  For example, a temporal connection alone does not automatically mean there’s causation.
  3. In a referral like this, the ECJ does not reexamine the facts. It is answering the specific questions of law, and basing its decision on the description of the facts sent up from below. The ECJ was acting on a mistaken premise that the science, in this case, was unclear. That premise came from the lower courts, and the ECJ did not err in following it: it did not reexamine the facts, and did not decide the case in front of it, it only addressed a specific legal question. In the lower courts that now will be expected to rule according to the ECJ’s decision, Sanofi Pasteur – the defendant – should provide the scientific evidence, and we can hope the court, as did the Court of Appeals who ruled on the case last, will follow it. It’s unclear how the case will end.

This is a complex decision. To explain it, I will start with some background on product liability law and European Union law with respect to the European court vaccine decision. Then I will address this case, and then the ruling itself. If you are short of time you can skip the background and go directly to the case, but I think those who want to really understand this will benefit from it.

Background: Product Liability and EU Law

Claims centered on problems with products are treated differently the regular claims of negligence under the law in most developed countries because of the reality of mass production. In modern markets, products are created by large (or small) companies through processes they control, usually according to a design they created that the consumer can, in some cases, customize but does not determine.

Customers may seek to research the product, but they inevitably, in almost all cases, have less information than the manufacturer about its design, its manufacturing processes, and its features. They cannot directly control the quality control and testing the product goes through. They have to choose whether to buy it or not – and they may or may not have real alternatives available – and they almost always do so on very limited information.

Reacting to this reality, and to the information and power gap between manufacturers and consumers, product liability law gives consumers real breaks in winning cases compared to negligence law. Basically, under United States law – and under the EU directive discussed here, Directive 85/374/EEC from July 25, 1985 (“the directive”), a customer has to prove that a product was defective, and that the defect caused legally recognizable damages (this is a major simplification of a complex body of law).

“Defect” in this case – under EU law – means that the product “does not provide the safety which a person is entitled to expect,” (article 6).  The customer does not have to show that the manufacturer acted unreasonably in manufacturing the product, that the quality control mechanisms were flawed, that the manufacturer should have known of the risk, and the other things a negligence case would require.

When the claim is that the design – as opposed to the manufacturing – of the product was flawed, some of this is brought back, since almost every design balances risk and benefits from a product. For example, adding more safety features to a bulldozer might make it less maneuverable and more cumbersome, or making a vaccine safer may reduce its effectiveness. The reader may well imagine many other examples. So reasonableness is relevant, but the goal is still to provide the plaintiffs breaks compared to a regular negligence case.

As set out in the opening paragraphs to the directive, the European Community was created, among other things, to facilitate economic relations among member states, including free movement of goods. If member states had laws offering differing levels of consumer protection from defective products, then there would be incentives for manufacturers to prefer some jurisdictions over others, which would adversely affect trade.

To avoid that, in 1985 the European Union passed a directive regulating product liability in all member states. A directive is a specific legal instrument in the EU: It requires national legislatures to adapt their national law to what the EU decreed, but it allows member states flexibility in how to implement the directive, allows differences among member states in the form implementation takes. In this case, in other words, the ruling allows France to use the approach they took to establishing causation, but does not require other states to follow exactly the same approach.

For completion, a regulation by the EU directly applies in the member states, and does not require national action to become law.

European court vaccine decision – The Case

Mr. J.W. received a series of hepatitis B vaccine starting in December 1998, and ending in July 1999. Starting in August 1999 his health deteriorated, and in Novmber 2000 he was diagnosed with multiple sclerosis (MS), which is an unpredictable, often disabling disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body.

The cause of MS is still unknown – scientists believe the disease is triggered by as-yet-unidentified environmental factor in a person who is genetically predisposed to respond.

Mr. W.’s health continued to deteriorate, leaving him disabled. On October 30, 2011, Mr. W. died.

His family sued Sanofi Pasteur, the manufacturer of the hepatitis B vaccine he received, claiming that the vaccine caused his MS. The law in France, mirroring the EU directive, required the plaintiffs to prove a defect in the product that caused his harm.

French law required that plaintiff prove both the existence of a defect and that the defect caused the harm with “serious, specific and consistent presumptions.” It also, apparently, made use of a number of legal presumptions.

Relevant to this case, the law seemed to suggest that temporal connection – a short period of time between vaccine and harm, and lack of personal or family history of the disease, can be such presumptions. If these factors exist, even if medical science does not show a clear link between product and harm, the court can find causation.

Note that presumptions are not absolute barriers. A defendant can counter – rebut – them, for example by showing that medical science goes against causation. In other words, this standard does not leave science out. It can help a plaintiff, however, win a case where the science is unclear or studies have not been done.

In September 2009, the trial court – the Grande Instance of Nanterre, which is a trial court that hears high value cases (translated in the ECJ decision as “regional court”) – found for the plaintiffs.

However, on appeal, the Court of Appeal of Versailles found that the plaintiffs’ evidence that the harm started shortly after the vaccine (in this case, apparently, the last and third dose) and that there was no family history of MS and Mr. W was healthy before the vaccine established a presumption of causation, but not a presumption of defect. In other words, the Court of Appeals basically rejected the claims and dismissed the case.

An appeal was brought to the highest court of the land, the Court de Cassation, which found that the Court of Appeal did not properly explain its reasoning.

The case was sent back down to a different court of appeal (as is usual, to avoid bias in the original court of appeal), the Court of Appeal of Paris. This court also overturned the trial’s judge decision, and explained finding against the plaintiffs by finding that the scientific evidence was against them on causation, as well:

  1. There was no scientific consensus that hepatitis B vaccine caused MS (note the formulation. The court did not conclude there was a scientific consensus against causation, either). In fact, national and international authorities think there isn’t a link between the category of diseases in question and the hepatitis B vaccine.
  2. Studies show no known cause for MS.
  3. A recent study suggests that by the time MS’s symptoms appear, the problems were already there months, even years.
  4. The vast majority of MS cases – over 90% – have no family history.

Based on this, temporal proximity and lack of family history, the Court of Appeal concluded, do not show causation.

Unlike a United States court of appeals, French courts of appeal are free to reexamine and decide again issues of fact. The case went back to the Cour de Cassation, which decided that before it can address the case, it needs guidance from the ECJ on the correct interpretation of EU law.

National high courts in Europe faced with this situation can put cases on hold and refer a legal question to the ECJ for decision. This is not common in the United States, though not completely unheard of – for example, federal appellate courts have ways of seeking help from state supreme courts on issues of state law. Referrals are, however, much more common in civil law systems in Europe. That is what happened here. The court sent three questions, but only two were addressed:

  1. Does article 4 of the EU directive allow member states to consider the type of facts here – temporal connection, factual assertions – as evidence proving causation even if medical research does not establish a causal link between the vaccine and the disease?
  2. If yes, can you use a set of presumptions, under which if certain factors are in place (like temporal links), a causal connection to the vaccine will be presumed?
  3. [this was an “if the answer to 1 is no question, and since the ECJ answered question 1 with “yes”, this was not addressed]

European court vaccine decision – The Ruling

Type of Evidence To Establish Causation:

What led to the news headlines is the fact that the court answered the first part with “yes”. But the headlines, in my view, miss what the decision actually said. Prof. Alex Stein provided a more nuanced view of this aspect, comparing it to the United States, and I recommend that analysis, though I disagree with the last part of it.

The basic finding of the ECJ decision was that,

when a court ruling on the merits of an action involving the liability of the producer of a vaccine due to an alleged defect in that vaccine, in the exercise of its exclusive jurisdiction to appraise the facts, may consider that, notwithstanding the finding that medical research neither establishes nor rules out the existence of a link between the administering of the vaccine and the occurrence of the victim’s disease, certain factual evidence relied on by the applicant constitutes serious, specific and consistent evidence enabling it to conclude that there is a defect in the vaccine and that there is a causal link between that defect and that disease.

This is what led to news articles concluding that the ECJ is allowing bringing cases against vaccine manufacturers when there’s no scientific evidence of causation. Well, yes and no. The operative language here is “medical research neither establishes nor rules out the existence of a link between the administering of the vaccine and the occurrence of the victim’s disease.” In other words, the court is not saying “national courts can ignore science.” The court is saying that when there is scientific uncertainty, when there is no clear evidence to either side of the causation equation, the plaintiff does not automatically lose their case for inability to prove the link scientifically, and can use external factors (like time and lack of family history) to convince the court to find a link anyway. If there is scientific evidence against causation, however, that shouldn’t work.

Note that the decision strongly emphasizes that manufacturers can, and should, be given opportunity to present counter evidence, including countering scientific evidence. The ECJ says:

any such conclusions can be drawn in a fully enlightened manner in each specific case by the court ruling on the merits of a given case only after that court has duly taken into consideration all the circumstances of the case before it, including in particular all the other explanatory evidence and arguments put forward by the producer challenging the relevance of the evidence relied on by the victim and questioning the plausibility, referred to in the preceding paragraph, of the explanation put forward by the victim.

A few points are in order. First, this is break for the plaintiffs compared to United States product liability cases (though not vaccine cases). In product liability cases generally in the United States, when claiming harm from a medical product, plaintiffs do have to provide scientific evidence of so-called general causation, that the product in question can cause the type of harm claimed (for example, Globetti v. Sandoz Pharmaceuticals Corp., 111 F. Supp. 2d 1174 (N.D. Ala. 2000)). More than that, they would have to meet standards of scientific credibility, with the court serving as gatekeeper to assess their experts and evidence under the Daubert standard. In contrast – and here I disagree with Prof. Stein – under the Althen standard (Althen v. Sec’y of Health & Human Servs., 418 F.3d 1274, 1278 (2005)) that applies in the National Vaccine Injury Compensation Program (vaccine court), petitioners in that court, even when they are not claiming a table injury and do not enjoy a presumption of causation, do not need to prove general causation. Petitioners just need to prove:

  1. a medical theory causally connecting the vaccination and the injury;
  2. a logical sequence of cause and effect showing that the vaccination was the reason for the injury; and
  3. a showing of a proximate temporal relationship between vaccination and injury.

The vaccine court’s standard is even more permissive than the EU standard, in that it applies even when there is no scientific uncertainty. In practice, however, that difference is meaningless, since if there is clear scientific evidence showing that the vaccine in question does not cause the harm, claimant would, under a correct decision, lose in both systems. In an Althen case, the government would bring that in and counter the theory (as was done in the Omnibus Autism Proceeding, where the court rejected a link between vaccines and autism; see Snyder v. Secretary of Health and Human Services Case No. 01-162V (pdf).

In a court ruling under the ECJ’s decision, clear scientific evidence against causation should counter these factors, which, again, should come into play when there is scientific uncertainty.

Second, this break for the plaintiffs is reasonable, under principles of product liability (and here, too, my reasoning is slightly different than that of Prof. Stein, though I don’t disagree with his). Since there is a power difference between manufacturers and consumers, it is justified to say that scientific uncertainty should not completely bar claims. Individual consumers are generally not able to conduct safety studies and create the evidence; manufacturers can at least help fund them.

Having uncertainty work against the manufacturer by allowing more types of proof in gives them incentives to do such studies. Requiring them to produce clear medical evidence when it doesn’t exist would be a very high bar, and product liability, accounting for the power differential, does not seek to make it as hard as that (at least in the EU). Note that this does not apply only to vaccines; this decision applies to products generally. In relation to vaccines specifically, as Prof. Stein said, the goal is to balance the need for an adequate supply of vaccines to protect society – which too much liability would undermine – and the need to protect the rights of victims of harmful products to be compensated. In that, you may think that this decision tilts more towards consumers – but remember, again, that this works only in cases of scientific uncertainty.

Third, it’s certainly possible – in fact, arguably, this is just that case, as Orac pointed out – that a court will mistakenly conclude there’s scientific uncertainty when there is none, and apply the factors where there’s no scientific causation, or apply them incorrectly – and it’s also possible the court will see scientific certainty where it does not exist, and not apply factors where it should.

Judges, as human actors, can make mistakes.  Judges ruling on matters of science or complex technology requiring a high degree of expertise may make more mistakes. As long as compensation is given to courts, and I don’t know of a better way to decide it, and courts are populated by humans, who are fallible, there can be mistakes. Courts try to address this by relying of experts, but that’s not foolproof, either – experts can be wrong, biased, or the court can reject valid expert opinion. Human activity is imperfect.

Note that this is not the court ruling on science. All the court is doing is ruling on if a person is eligible for compensation.  Sometimes, the science isn’t ready, and the court has to decide what to do. Rejecting a case because the science hasn’t been done carries costs: what if plaintiff is right about causation? The court has to balance individual justice with absolute truth. Rules like the French causation rule are a way to try and do that. It’s not the only way, but it’s one way.

Fourth, the application of this principle in this case should lead to a finding of no liability – because as explained below, this is not a case of scientific uncertainty. That said, the ECJ did not make a mistake here. The ECJ was determining a legal principle based on lower courts decisions. Those suggested scientific uncertainty. The ECJ stated that twice – in paragraph 18, referring to the “finding that medical research neither establishes nor rules out the existence of a link between the administering of the vaccine and the occurrence of the victim’s disease,” and in paragraph 30, where it explained that the referring court mentioned that “medical research neither confirms nor rules out a link between the administering of the vaccine and the occurrence of multiple sclerosis[.]”

When the case goes back to the lower court, the ECJ made it clear that the manufacturer can counter with scientific evidence, and the manufacturer should. As pointed by Orac, again, the specific factors can also be challenged, and it’s perfectly appropriate to do so (and the Court of Appeals in Paris seemed to accept such a challenge).

Do Presumptions Apply?

Under French law, certain factors – like proximity and lack of family history – create presumptions that the product caused the harm, according to the decision. The Cour de Cassation asked the ECJ whether that contradicts the directive, and the ECJ said yes: because under article 6 of the directive the burden of proof is on the plaintiff, and because presumptions, operatively, shift the burden of proof, you cannot have presumptions about causation.

Courts have to decide whether there is causation, in cases of scientific uncertainty, on a case-by-case basis, though they may consider factors like proximity in time. This is a break for the defendants – even if there is scientific uncertainty, the plaintiff still bears the responsibility to prove the case under the preponderance of evidence standard. It won’t matter in cases where the evidence clearly favors one party or the other, but it can matter where the evidence is close: if the plaintiff did not make a strong case, they can lose.

MS and Hepatitis B vaccine

In spite of the language in the complaint, abundant scientific evidence finds no link between hepatitis B vaccines and multiple sclerosis. As explained by Steve Novella:

Systematic reviews from 20032011, and 2017 all found no increased risk of MS after any vaccination, specifically including hepatitis B. The 2017 review looked at 62 studies of vaccines and MS risk. Why was this not enough?

An example of a relatively recent study that also showed no correlation between hepatitis B and MS. Other references are included in the CDC’s discussion of this issue.

In a thorough discussion of the issue (pdf), the World Health Organization stated:

GACVS considers that data from spontaneous reports and epidemiological studies do not support a causal relationship between MS and hepatitis B vaccine.

While there are some limited studies claiming a link, based on case reports, the WHO explains:

…analysis of data from spontaneous reports and epidemiological studies does not support a causal relationship between MS and hepatitis B vaccine. The most likely explanation is a coincidental association.

In short, this was not a good case to claim scientific uncertainty. It is a case where the lower courts should have rejected the claim as against the scientific evidence. However, French Courts have not approached the issue that way, and instead, worked to provide compensation to post Hepatitis B vaccine MS cases, using arguments that are often very, very problematic.

The ECJ decision allows them to continue to do so, if they so choose – but by removing presumptions forces them to directly confront the science contradicting compensation in such cases. We will have to see where the courts go.


It’s important to reiterate, again, what the European court vaccine decision is not. It’s not a decision that says courts can ignore science. It’s not a decision that should allow anti-vaccine activists to bring counter-science claims, like the claim that vaccines cause autism.

And it’s not a decision that requires all member states to follow the French law. It is a decision that allows, even encourages, member states, in situations of scientific uncertainty in product liability – not just vaccines – to consider other factors, such as temporal proximity of harm to vaccine, and compensate a plaintiff even without clear scientific evidence supporting causation. It’s a break for the plaintiffs, certainly.

But European court vaccine decision is not a blank check to blame vaccines for any problem, and it’s not unreasonable to place the burden of scientific uncertainty, when there are other factors that can support causation, on large manufacturers over consumers.

Link to the European Court vaccine decision – EU Sanofi Pasteur N.W decision

Dorit Rubinstein Reiss
This article is by Dorit Rubinstein Reiss, Professor of Law at the University of California Hastings College of the Law (San Francisco, CA), is a frequent contributor to this and many other blogs, providing in-depth, and intellectually stimulating, articles about vaccines, medical issues, social policy and the law. 

Professor Reiss writes extensively in law journals about the social and legal policies of vaccination. Additionally, Reiss is also member of the Parent Advisory Board of Voices for Vaccines, a parent-led organization that supports and advocates for on-time vaccination and the reduction of vaccine-preventable disease.