Who bears the risk of the appearance of damage?

 From Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus That Caused It by Gina Kolata.  Page 160. 

Until President Ford launched his swine flu campaign, few outside of drug companies had thought much about who was liable when someone claimed injury from a vaccine. There had, however, been one notable vaccine lawsuit, and it had sent chills through the industry, making the companies wary of what might happen with a swine flu vaccination campaign.

The litigation involved a polio vaccine, made by Wyeth Laboratories, and it had concluded in 1974, just two years before the swine flu program was announced. The case, known as Reyes v. Wyeth Laboratories, Inc., involved an eight-month-old baby who got polio after receiving a Wyeth vaccine. Experts testified that the company had done nothing wrong and that the baby’s case of polio was probably not related to the vaccine. But Wyeth lost and was “ordered to pay $200,000 to the child’s family. Wyeth appealed to the Supreme Court, but the Court refused to hear the case and the judgment against the company held.

Neustadt and Fineberg, in their postmortem on the swine flu affair, tartly summed up what the Reyes case meant to vaccine manufacturers. The courts had ruled that Wyeth had failed to adequately warn of its vaccine’s dangers. “Never mind that the company had included in cartons for shipment a printed form which did contain adequate warning. Never mind that experts had testified at trial that this particular case was not vaccine-related. Wyeth would pay (and did). The suffering was real and Wyeth had the only deep pocket available.”

What might happen if an entire nation got a flu vaccine? By chance alone, tens of thousands of people who were vaccinated would come down with some illness after getting a flu shot and some would die. After all, tens of thousands of people get sick and many die every day. That is simply the normal course of events. But what if some of these people claimed that the vaccine made them sick, or led to the deaths of loved ones? What would a jury say if confronted, for example, with a child who began having severe epileptic seizures within hours or days of being immunized against swine flu? How sympathetic might a jury be to a large company that argued that epilepsy was coincidental and not related to the vaccine when they saw the tearful parents and the concerned doctors who argued the opposite? Or how about the young woman who got multiple sclerosis after her flu shot? Or the middle-aged man who suffered a heart attack or stroke? Then multiply those cases by tens of thousands, and companies could envision financial catastrophe.

Even worse, what if the vaccine really did cause a disease, albeit one that was not known when the vaccine campaign began? How well would companies fare if plaintiffs’ lawyers argued that the companies should have known, or that they actually did know about the association between the vaccine and the disease—that obscure and unpublished data buried in their files actually told them about it but they hid those findings and hoped no one would ever discover them?

It simply was not worth taking a chance, the companies reasoned. No matter if they warned of any and all known dangers of the vaccine. No matter if they could easily explain to the scientific community the illnesses and deaths that were bound to occur by coincidence when more than 100 million people were vaccinated. The fact remained that the companies could be sued, and they could lose big. Even if they won, they could be saddled with immense costs of defending themselves against a barrage of lawsuits.

Dr. Hans H. Neumann, who was director of preventive medicine at the New Haven Department of Health, explained the problem in a letter to The New York Times. He wrote that if Americans have flu shots in the numbers predicted, as many as 2,300 will have strokes and 7,000 will have heart attacks within two days of being immunized. “Why? Because that is the number statistically expected, flu shots or no flu shots,” he wrote. “Yet can one expect a person who received a flu shot at noon and who that same night had a stroke not to associate somehow the two in his mind? Post hoc, ergo propter hoc,” he added.

In addition, Neumann wrote in his letter, within a week after receiving flu shots, 45 people will develop encephalitis and more than 9,000 will get pneumonia. Nine hundred will die of pneumonia. “Sequential to the immunizations? Yes, but not a consequence of them,” he said. “These are only a few examples of what is bound to happen the day and the week after immunizations.”

Neumann cautioned: “It is one thing to see matters objectively in light of statistical expectations. It is quite another when it affects one personally. Who can blame someone for assuming the events are linked? Hence, the presumption of tort and the liability problem that is expected.