by Dr Paul A.Offit
In the spring of 2001, thimerosal (an ethylmercury-containing preservative) was removed from all routinely recommended vaccines given to young infants. As a consequence, lawsuits claiming that vaccines cause neurological damage, specifically autism, are now quietly amassing across the country. Soon, judges and jurors may decide whether thimerosal in vaccines caused harm.
Removal of thimerosal was precipitated by the finding that the level of mercury in vaccines exceeded safety guidelines recommended by the Environmental Protection Agency. Although the level didn't exceed guidelines recommended by the Food and Drug Administration (the agency charged with determining vaccine safety), thimerosal was removed as a precautionary measure. Not surprisingly, some parents felt that thimerosal was removed from vaccines because it was harmful, and subsequently worried that thimerosal might cause autism, a developmental disorder characterized by difficulties with language, communication and behavior.
So, are there any scientific data supporting claims that vaccines containing thimerosal cause autism or any other form of neurological damage? Parents can be reassured by the following facts:
Taken together, these findings should reassure parents that ethylmercury contained in vaccines does not cause autism.
If the question of whether thimerosal causes autism is a scientific one, why does society turn to judges and jurors for answers? How did the courts become the final arbiters of scientific truth? It happened on Jan. 17, 1957, at 5:50 p.m., in Oakland, Calif., when a jury reluctantly opened Pandora's box.
The case involved a little girl, Anne Gottsdanker, who was paralyzed soon after receiving a shot of polio vaccine. The vaccine, pioneered by researcher Jonas Salk, was made by killing polio virus with the chemical formaldehyde. Although five companies made the vaccine, only one company -- Cutter Laboratories of Berkeley, Calif. -- had a problem. Because of Cutter's vaccine, 70,000 children were inadvertently inoculated with live polio virus; 23,000 were temporarily paralyzed; 164 were severely paralyzed; and 10 were killed. It was the worst pharmaceutical disaster in American history. The parents of Anne Gottsdanker sued Cutter Laboratories for negligence.
For six weeks, the jury heard testimony that revealed an industry-wide problem: Wyeth Laboratories also made a polio vaccine that caused paralysis; safety tests at the time were not sensitive enough to detect small quantities of live virus; and all companies were later found to have difficulties inactivating polio virus. By a vote of 10 to 2, the jury found that Cutter was not negligent.
But negligence wasn't the only issue. Cutter was also sued for breach of implied warranty -- a vaccine made to prevent paralysis shouldn't cause paralysis. By a separate vote of 11 to 1, the jury agreed, and awarded Anne $125,000. Pharmaceutical companies were now absolutely responsible for the safety of their products. Cutter protested: "We cannot be warrantors of the future, guarantors of the unknown." The jury's decision meant that the courts would now be the final arbiters of medical-product safety. The court's record is troublesome.
In 1956, the Merrell Company (later Merrell Dow) made a drug to relieve the nausea and vomiting of early pregnancy (morning sickness). The drug, Bendectin, was used in up to 40% of pregnancies in the U.S.
In 1982, lawyers for Mary Oxendine, a child born with a shortened forearm and web-like hand following her mother's use of Bendectin, sued Merrell Dow for $20 million. Although all studies performed at the time found that Bendectin did not cause birth defects, the jury awarded Mary $750,000. By 1987, Merrell Dow, although they won 17 of 22 lawsuits, had spent $100 million in legal fees and awards. They decided to stop making Bendectin. A company spokesman said: "We wouldn't bring Bendectin back if we won every lawsuit." One year later, the president of a major pharmaceutical company was more direct: "Who in his right mind would work on a product today that would be used by a pregnant woman?"
Within two years of discontinuing Bendectin, the incidence of hospitalization for dehydration during early pregnancy doubled -- the incidence of birth defects was unchanged. Bendectin has never been effectively replaced.
On July 1, 1981, Katie Wells was born with birth defects that included abnormalities of her arm, shoulder, hand, lip and optic nerve. Katie's mother, not realizing that she was pregnant, continued to use the spermicidal jelly OrthoGynol, a product made by Ortho Pharmaceuticals. The active ingredient in OrthoGynol was Nonoxynol-9. In 1986 Katie Wells sued Ortho Pharmaceuticals claiming that Nonoxynol-9 caused her birth defects.
In 1982, four years before the lawsuit, a study comparing the outcomes of 50,282 pregnancies had found that Nonoxynol-9 did not cause any major or minor birth defects. The trial judge, Marvin Shoob, decided that deformities of Katie's arm, shoulder, and hand were caused by Nonoxynol-9, but that her lip and optic nerve defects were not. No studies at the time, or since, support that decision. Shoob awarded Katie $5.1 million -- an award upheld by a federal court of appeals. The New York Times called the decision an "intellectual embarrassment."
In 1992, then-FDA Director David Kessler decided that there was not sufficient evidence that silicone-filled breast implants were safe. Mr. Kessler, in a precautionary move similar to the removal of thimerosal, asked manufacturers to withdraw breast implants from the market.
Mr. Kessler's action precipitated an onslaught of litigation. The number of lawsuits directed against Dow Corning, the principal manufacturer of breast implants, increased from 200 in 1991 to 10,000 in 1992. Women with silicone-filled breast implants claimed a variety of chronic symptoms including fever, headache, fatigue, rash, joint pains, muscle aches, sleeplessness, and dryness of the eyes and mouth, collectively called "connective-tissue diseases."
Lawyers consolidated thousands of cases and, in 1994, settled the largest class-action lawsuit in history -- $4.25 billion. During and subsequent to the settlement, seven well-controlled, carefully performed scientific studies found that breast implants didn't cause connective-tissue diseases. In 1999, the Institute of Medicine also concluded that breast implants did not cause chronic disease. Dow Corning had already filed for bankruptcy.
Judges and juries are asked to know more than those who regulate, license and approve medical products. They are asked to know more about pharmacology, virology, microbiology and pathogenesis than the FDA; more about epidemiology than the Centers for Disease Control and Prevention; and more about toxicology than the EPA. Russ Herman, a former president of the Association of Trial Lawyers of America, has defended the role of judges and juries in deciding product safety, "[T]he courts are an institution established for the resolution of disputes, not arbiters of scientific truth. History shows that many 'facts' lack staying power." However, the facts that Bendectin and Nonoxynol-9 didn't cause birth defects, and that breast implants didn't cause connective-tissue diseases, have been maddeningly stubborn.
Soon, the perception of vaccines -- one of the most important weapons in public health -- may depend on the ability of judges and jurors to understand and critically evaluate the science behind the assertion that vaccines cause autism.
"In terror Pandora clapped the lid down, but too late."
Dr. Offit is chief of the division of infectious diseases at the Children's Hospital of Philadelphia.
This article originally appeared in the The Wall Street Journal on February 9, 2004, and is reproduced with the permission of the author.