Investigation questions gardasil clinical trial safety data

“If the purpose of a clinical trial is to establish the safety and efficacy of a new product, whether it’s a vaccine or something else, I would expect that they gathered all relevant data, including whether it had side effects or not.”  — Trudo Lemmens, University of Toronto


While Merck & Co. and many health authorities share the view that the benefits of the human papillomavirus vaccine (HPV), Gardasil, outweigh the risks, an eight-month investigation by medical journalist Frederick Joelving, which was published by the online magazine Slate, confirms that clinical drug trials Merck conducted in 2002 were inadequately designed to reliably assess the safety of the vaccine pre-licensure.1

No Objective Reporting of Potential Side Effects

According to Merck, Gardasil’s safety profile relied heavily on data from two randomized, placebo-controlled trials (Future 1 and Future 2) involving more than 25,000 females and males in several countries, including the United States.

Approximately 2,300 pages of documents obtained through Freedom of Information Act (FOIA) requests, as well as interviews with five study participants, were evaluated during the investigation. Slate concluded that the clinical trial protocol was flawed from the start, although government regulators still used the flawed safety data as the basis for approving Gardasil vaccine for use in young girls and women.

The key piece of evidence arguing against proof of safety pre-licensure is that trial investigators registered complaints of adverse health effects following Gardasil administration by study subjects not as potential vaccine-related adverse events, but as “new medical history.” In fact, the individual clinical trial investigators used personal judgment to choose whether to report health problems as potential Gardasil side effects worthy of further evaluation. Those medical conditions recorded in “new medical history” were allotted one line, lacked details measuring severity, duration, outcome or overall seriousness, and were reserved for issues unreleated to the vaccine. There was no indication in the study’s documents that regulators should use “new medical history” as a safety metric.

Furthermore, Merck designed the clinical trial safety analysis to restrict vaccine adverse event reporting to only those events recorded within 14 days following each dose of the three Gardasil injections administered to participants. Any illnesses or symptoms occurring outside the time period were recorded on a single line as part of the “new medical history” worksheet.

Interviews with Study Subjects Support Questionable Methods

Three female Future 2 clinical trial participants shared their own experience with Slate.

Miam Donslund said that her flu-like symptoms and one hospitalization from infection following immunization were recorded as “new medical history.” Today, she lives with severe joint pain and regularly uses crutches, yet does not have a diagnosis. Stine Sorensen experienced general discomfort, headaches and fatigue following Gardasil vaccination and reported these to the study personnel, but nothing is listed in her trial records.

The health outcome was the worst for Future 2 trial participant Keisa Lyng. Lyng’s grandmother had died of cervical cancer, so when she was offered a spot in the Gardasil trial in 2002 for $500, she opted to participate without hesitation. After her second Gardasil shot on Nov. 14, 2002, Lyng started to experience flu-like symptoms, joint and muscle pains, headaches and debilitating fatigue. Her family doctor started documenting her problems on March 20, 2003, nine days after her third and final Gardasil injection.

Lyng shared her symptoms with study personnel at every visit during the four-year trial, yet there was no mention of these conditions in her Future 2 trial records. The trial investigator who dealt with both Sorensen and Lyng declined an interview with Slate, noting only that she followed the study’s protocol.

Lyng eventually had to quit school and it wasn’t until 2016 that she received a diagnosis of chronic fatigue syndrome, an illness that has roots in a compromised immune system. There have been hundreds of other women reporting the same health issues following Gardasil vaccination, but most accounts have been dismissed as unreliable “anecdotal” evidence.

Officials Uncertain About Merck’s Approach

When reviewing Merck’s marketing application for Gardasil, the European Medicines Agency called the company’s approach “unconventional and suboptimal,” but ultimately considered the trial safety data to be usable enough for approving licensure.

“If I were a research subject, I would feel betrayed,” Trudo Lemmens, a University of Toronto professor of health law and policy told Slate. “If the purpose of a clinical trial is to establish the safety and efficacy of a new product, whether it’s a vaccine or something else, I would expect that they gathered all relevant data, including whether it had side effects or not.”1

Slate’s science editor, Susan Matthews, explained the reason for the magazine’s investigation, “the truth is that science can be imperfect, and evidence can be incomplete. When that is the case, we should be upfront and transparent about it—in fact, I believe that doing so serves to bolster our credibility rather than diminish it.”2

1 Joelving F. What the Gardasil Testing May Have Missed. Slate Dec. 17, 2007.
2 Matthews S. Why is Slate Questioning Gardasil? Slate Dec. 17, 2017.


By Patrice La Vigne / Staff Writer for The Vaccine Reaction
(Source:; January 10, 2018;
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