Wednesday, February 23, 2011
by: Rosemary Mathis, Director of SANE VAX, INC.
All drugs are associated with some risks of adverse reactions and vaccines are no exception. In weighing risks versus benefits, one has to keep in mind that vaccines represent a special category of drugs since they are generally given to healthy individuals. If there are uncertain benefits from a vaccine, only a small level of risk of harmful effects may be acceptable. If the benefits are certain, then a greater risk of side effects may be tolerated. Here I review the current evidence which indicates that the former case applies to Gardasil, the quadrivalent human papillomavirus (qHPV) vaccine:
1) The efficacy of Gardasil in preventing cervical cancer has not been demonstrated and the marketing campaign has been misleading. The efficacy of Gardasil remains unsubstantiated since the vaccine hasn’t been adequately tested on the primary age group to which it is currently given.
Merck promoted Gardasil primarily as a vaccine against cervical cancer, rather than promoting it as a vaccine against HPV infection or sexually transmitted diseases.
According to recent reports published in two highly respected scientific journals, Nature Biotechnology and Journal of American Medical Association (JAMA):
“Most genital infections are asymptomatic and resolve spontaneously, but the virus can persist and cause precancerous lesions that can become malignant over the subsequent 20-30 years.” (Nature Biotechnology, 2007 2)
“So how should a parent, physician, politician, or anyone else decide whether it is a good thing to give young girls a vaccine that partly prevents infection caused by a sexually transmitted disease (HPV infection), an infection that in a few cases will cause cancer 20 to 40 years from now? (JAMA, 2009 3).
The fact is that malignant cervical cancer takes decades to develop and yet the longest clinical trial on Gardasil was only four years in duration. In other words, Gardasil was never shown to prevent cervical cancer [emphasis added]. Furthermore, in all clinical trials conducted by Merck the cervical intraepithelial neoplasia (CIN) 2/3 precancerous lesion was used as the efficacy endpoint for evaluating the Gardasil. What is the problem with using the CIN 2/3 lesion as the standard for efficacy? First, if the marketing claim for Gardasil is that the vaccine “protects against cervical cancer” then cervical cancer should have been used as the endpoint for efficacy, not a surrogate marker such as a CIN 2/3 precancerous lesion [emphasis added]. Second, in the natural course of cervical cancer, only a small fraction of the CIN 2 lesions will progress to CIN 3 lesions and only a small fraction of CIN 3 lesions will eventually progress to cervical cancer. Furthermore, even CIN 3 lesions are heterogeneous (there are early small lesions and old advanced lesions and we do not know what proportion of the small lesions, which serve as clinical endpoints in current studies, would persist to become large, advanced CIN3 lesions). Therefore, in any female population (and that includes those who have undergone Gardasil clinical trials) there are many more CIN 2 lesions than a combination of CIN 3 lesions and cervical cancers. As a result, the vast majority of the “CIN 2/3 or worse” cases used for evaluation of efficacy, and listed in Merck’s report to FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC Background Document on Gardasil HPV Quadrivalent Vaccine 8), must have been CIN 2 lesions.