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Originally published in the March/April 2007 Fisique newsletter.
Merck's new Human Papilloma Virus (HPV) vaccine, Gardasil, is touted as a solution to cervical cancer. A few people have asked me whether I recommend the vaccine, this article is meant to provide an overview of alternative viewpoints and my guidance for you and your family.
I've started with the definition and review of a few facts pertaining to cervical cancer and HPV before examining Gardasil's ingredients and efficacy. My closing commentary explores a few questions worth asking and raises important risks of rushing a vaccine to the mass market.
- What is Cervical Cancer?
- What is HPV?
- What is Merck's New Vaccine, Gardasil?
- Efficacy
- Adverse Reactions
- Commentary
- References
Cervical cancer, also known as cancer of the cervix, affects the lower part of the uterus where it joins at the top of the vagina. Once the number one cancer killer of women, cervical cancer now ranks 13th in cancer deaths for women in the United States. The American death rate due to cervical cancer dropped 74% between 1955 and 1992, and continues to drop every year. Half of all cases occur between the age of 35 and 45.1
The significant drop in occurrence has mainly been attributed to increased use of condoms and regular Pap smears. HPV is entirely preventable and responds well to treatment when caught early.2
A small number of cases of cervical cancer do not have an associated HPV. Accordingly, the possibility that HPV is not the full cause of cervical cancer must be considered. Researchers and FDA scientists are investigating whether abnormal cancer cells are simply a good environment for HPV to reproduce.3
There are over 100 strains of HPV, and the majority are generally associated with warts. Only 30 of these strains affect the genital area, and about 10 have been associated with cervical cancer.4 HPV is transmitted through skin-to-skin contract, and HPV is the most commonly sexually transmitted disease (STD) in the US.5 Two strains, 16 and 18, are believed to cause 60-70% of cervical cancer cases.6
Due to its ease of transmission, HPV is found in humans of all ages, including infants and toddlers. The virus is generally considered innocuous and immunity is natural. 50% of sexually active people will acquire genital HPV infection at some point in their lives. 80% of women will have acquired the genital virus by age 50.4
70% of women naturally rid themselves of the virus without symptoms within 18 months, and 90% within two years.4 The development of cervical cancer is considered rare. When detected at an early stage, cervical cancer's 5-year survival rate is over 90%.2
On a base of 20 million current HPV infections in the US, less than 1% of women will develop invasive cervical cancer. Most of these women will not have received regular Pap screening. Of those who develop invasive lesions, 37% will die (1% of all cancer deaths).4
In symptomatic cases of HPV infection, warts may develop in the genital area. These may be treated topically or left to disappear on their own. Years of chronic infection have been associated with pre-cancerous cells in the cervix, eventually leading to cancer if left untreated. Contributors to chronic infection include smoking, long-term use of oral contraceptives, and co-infection with other STDs such as HIV, herpes, and Chlamydia.7
Gardasil includes virus-like particles of four strains of HPV: 6, 11, 16, 18. The vaccine works by triggering antibody response against the four strains and claims to protect women from cervical cancer, cervical dysplasia, and genital warts.
It is administered in three doses over a period of 6 months. The vaccine is recommended for girls and women aged 9 to 26 years. Gardasil is not a substitute for regular cervical cancer screening.8
To be most effective, women must receive all three doses within six months and have had no prior exposure to the four strains included in the vaccine. The vaccine does not help the body overcome current infections. Subjects with prior exposure to the strains and who had not cleared the virus from their system before the trial showed higher rates of cervical neoplasia (abnormal cancer cell precursors).9
The maximum median duration of the vaccine trial was four years. However, it takes 8 to 12 years for pre-cancerous cells to develop into invasive cervical cancer. Since the trial wasn't long enough to measure actual cancer development, researchers used abnormal pre-cancerous cells as a substitute measure.10
Studies show that the vaccine is nearly 100% effective in protecting women with no prior exposure from the four HPV strains in Gardasil.4 However, this group still developed pre-cancerous markers associated with other HPV strains.3 Since women are not tested for HPV before vaccination, these figures mainly apply to recipients who have never been sexually active.
The overall results of the study, which are most comparable to expected efficacy in the general population, showed a 12% reduction in pre-cancerous cells associated with any type of HPV.11 With current infection rates and Merck's Gardasil trial results, some number crunching tells us that 1 million girls must be vaccinated to prevent 4-5 cervical cancers. Or, US$360 million must be spent to prevent 1-2 deaths.
The placebo used in the control trial contained aluminum rather than a non-reactive saline solution.12 Aluminum has been shown to cause nerve cell death13 and adjuvants (immune suppressants) included in vaccines allow aluminum to enter the brain.14 The non-saline placebo makes the vaccine group's adverse reactions look artificially low.
On a base of about 20,000 trial participants, 60% experienced adverse effects including: including headache, fever, nausea, dizziness, vomiting, diarrhea, and myalgia. Gardasil recipients had more serious reactions such as gastroenteritis, appendicitis, pelvic inflammatory disease, asthma, bronchospasm, and arthritis.11
There were five cases where children with birth defects were born to women who had received the vaccine around the time of conception.9
There were 102 serious adverse events, including 17 deaths, in the vaccine trial. However, trial investigators dismissed these events as unrelated to the vaccine.15
It has been established in the medical community that cervical cancer is entirely preventable with good regimen and regular Pap screening. Like most vaccines in history, Gardasil is being introduced when occurrence of the disease has dropped significantly and continues to do so. Regular Pap smears will remain necessary despite the vaccine. The long-term duration of immunity, efficacy, and safety of the vaccine has not been established.
The vaccine could be beneficial for those who have nutritional deficiencies, multiple partners, not been exposed to the four HPV strains in Gardasil, and do not oblige regular preventative measures.
Are the risks and tangible costs really worth it? Will immunity last 20 or more years, the time frame in which cervical cancer is typically diagnosed? Vaccine candidates are not currently tested for HPV before administration, nor is there a routine office test that identifies the specific HPV strains. Vaccinating HPV carrying individuals may result in immune suppression and increased development of pre-cancerous cells.
Gardasil, much like the Hepatitis B vaccine, is being rushed to the mass market. The Hepatitis B vaccine is now the most reported vaccine in the Vaccine Adverse Event Reporting System (VAERS).3 Furthermore, adverse reactions to vaccines are notoriously under-reported. It is estimated that the 30,000 reactions reported to the VAERS annually represent only 10% of adverse reactions.10
Vaccine manufacturers are legally protected when their product causes harm, which does not inspire confidence in the brief vaccine trial. To review the media's involvement in selling vaccines, it may be worth reviewing the flu vaccine feature in my November newsletter.
Now, watch for Gardasil's approval for use on men and Glaxo's Cervarix vaccine: coming soon!
(1) Various authors. "American Cancer Society Guideline for the Early Detection of Cervical Neoplasia and Cancer" CA: A Cancer Journal for Clinicians, American Cancer Society. 2002; 52:342-362.
(2) Lee, Nancy C. "Testimony on Cervical Cancer" US Department of Health and Human services, March 16, 1999.
(3) Dolan, Moira Terese. "Not So Miraculous: Telling the Truth about the New Vaccine Gardasil" Medical Accountability Network, 2006.
(4) "Genital HPV Infection - CDC Fact Sheet" Centers for Disease Control and Prevention, May 2004.
(5) "Product Approval Information - Licensing Action: Gardasil Questions and Answers" Center for Biologics Evaluation and Research, US Food and Drug Administration. June 8, 2006.
(6) Sweet, Marcella. "Women to Women gives Gardasil guarded reviews" Women to Women, Februrary 9, 2007.
(7) "Cancer Facts and Figures 2005" Atlanta: American Cancer Society; 2005. Pages 27-29.
(8) "Gardasil Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine" Merck Vaccines: Product Features.
(9) "Gardasil® HPV vaccine: Cancer cause or Cancer preventive?" Vaccination Liberation Information, June 9, 2006.
(10) Young, Clayton. "OBGYN Questions HPV Vaccine Gardasil" (Open letter to The American College of Obstetricians and Gynecologists), PROVE, November 21, 2006.
(11) "Gardasil Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine" (Package Insert) Merck & Co, Inc: April 2007.
(12) "VRBPAC Background Document: Gardasil™ HPV Quadrivalent Vaccine" US Food and Drug Administration, May 18, 2006.
(13) Kawahara M, Kato M, Kuroda Y. "Effects of aluminum on the neurotoxicity of primary cultured neurons and on the aggregation of beta-amyloid protein" PubMed: 2001 May 15;55(2):211-7.
(14) Sahin G, Varol I, Temizer A, Benli K, Demirdamar R, Duru S. "Determination of aluminum levels in the kidney, liver, and brain of mice treated with aluminum hydroxide" PubMed: 1994 Apr-May;41(1-2):129-35.
(15) "Merck's Gardasil Vaccine Not Proven Safe for Little Girls" National Vaccine Information Center, June 27, 2006.
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