The Journal of Scientific Practice and Integrity (Dec 2020)
Has the HPV vaccine approval ushered in an era of over-prevention?
Abstract
Gardasil (Merck’s quadrivalent HPV vaccine) is the first vaccine in history to have been granted the FDA’s accelerated approval and fast track. Using unpublished documents and data, we investigated the impact of US regulators’ choices on the quality of available evidence regarding the vaccine’s efficacy in preventing high-grade cervical lesions, which are precursors of cervical cancer. We found that, as early as 2001, the accelerated approval and fast track procedures prompted FDA advisory committees to make methodological choices such that only weak claims could be made regarding the vaccine’s efficacy and to approve a product whose benefit-to-harm ratio cannot be appropriately assessed. By giving more weight to the HPV vaccine’s hypothetical promises rather than to compliance with best methodological principles, regulatory authorities’ decisions turned out to be more favorable to commercial interests than to public health thereby allowing HPV vaccine manufacturers to escape the usual burden of proof while generating huge profits. Published and unpublished results of pre-marketing trials strongly suggest that introduction of the vaccine will not lead to the expected reduction in the incidence of high-grade cervical lesions, let alone of cervical cancer. The available HPV vaccines do not target all high-risk HPV strains. Consequently, screening must be maintained. The marketing of Gardasil has thus inaugurated a new form of medical overuse in the field of prevention: the introduction of a low-value primary prevention measure (vaccination) whose effectiveness can never be completely assessed since the secondary prevention measure (screening) cannot be removed. Meanwhile, health authorities promote the product and society bears the costs of vaccination campaigns and health risks. This is a concerning outcome. Such over-prevention creates a societal and individual burden of unnecessary medical expansion that undermines science.