Research findings from a safety review published in JAMA on Tuesday indicated that Merck & Co.'s cervical cancer vaccine Gardasil was associated with higher rates of blood clots and fainting compared with other vaccines, but that there was no evidence severe adverse events were caused by the product. In a separate article in JAMA, researchers who studied Merck's marketing practices for the vaccine questioned the "methods and messages by which [Gardasil] was marketed," including the provision of grants to certain professional medical associations that used the funds to promote Gardasil with a strategy similar to the company's marketing campaign for the vaccine.
In the safety study, researchers at the US Centers for Disease Control and Prevention analysed over 12 400 reports of adverse events filed between June 2006 through December 2008 by girls and women following immunisation with Gardasil. "Most of the [adverse event] rates were not greater" than rates observed with other vaccines, the researchers noted, "but there was disproportional reporting" of fainting and venous thromboembolic events (VTE).
Lead author Barbara Slade said that approximately 6 percent of all reports filed were classified as serious adverse events, which included 32 deaths. She noted, however, that there is no evidence the vaccine caused the deaths. Regarding the higher rate of VTE in girls and women who received Gardasil, researchers suggested the data should be viewed with caution since 90 percent of the cases also involved other risk factors. Overall, the researchers concluded that "the post-licensure safety profile presented here is broadly consistent with safety data from pre-licensure trials."
Separately, in regards to the marketing analysis, researchers from Columbia University said the American College Health Association, the American Society for Colposcopy and Cervical Pathology, and the Society of Gynecologic Oncologists promoted Gardasil with the help of funds provided by Merck. According to the authors, the groups used the funding to prepare educational materials and lectures that did not address the "full complexity of issues surrounding the vaccine" or "provide balanced recommendations" on the product's risks and benefits. Co-author Sheila Rothman remarked: "I think what happened here was that marketing and medical education got blurred."
Merck acknowledged that the company distributed a total of about $750,000 among the three groups in order to help them "develop, independent of Merck, their own information that was distributed to their membership," explained Richard Haupt, the drugmaker's head of the Gardasil clinical programme. He added that "our activities with these societies were done in an appropriate and independent manner." Officials with the associations denied they acted inappropriately, saying the funds paid for educational efforts about the vaccine, but did not influence the content of the groups' programmes.
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