|Target disease||human papillomavirus (Types 16, 18, 6, and 11)|
|Pregnancy cat.||B (US)|
|Legal status||℞-only (US)|
|(what is this?)|
Gardasil (Merck & Co.), also known as Gardisil or Silgard or recombinant human papillomavirus vaccine [types 6, 11, 16, 18], is a vaccine for use in the prevention of certain strains of human papillomavirus (HPV), specifically HPV types 6, 11, 16 and 18. HPV types 16 and 18 cause an estimated 70% of cervical cancers, and are responsible for most HPV-induced anal, vulvar, vaginal, and penile cancer cases. HPV types 6 and 11 cause an estimated 90% of genital warts cases. Though it does not treat existing infection, vaccination is still recommended for HPV positive individuals, as it may protect against one or more different strains of the disease. The risk of HPV rates in sexually active women ages 14–24 are also rising each year by 27%. The HPV strains that Gardasil protects against are sexually transmitted. It was approved in the US on June 8, 2006 by the U.S. Food and Drug Administration (FDA). In 2008, Gardasil was approved in 41 of U.S. states. The Gardasil vaccine has also been approved in 120 other countries. The FDA recommends vaccination before adolescence and potential sexual activity.
- 1 Development history
- 2 Indications and prevalence
- 3 Ingredients
- 4 Efficacy
- 5 Safety
- 6 Public health advantages
- 7 Political and other controversy
- 8 References
- 9 External links
The research that led to the development of the vaccine began in the 1980s by groups at the University of Rochester, Georgetown University, and the US National Cancer Institute (NCI). In 1991, Australian investigators Jian Zhou and Ian Frazer at The University of Queensland found a way to form non-infectious virus-like particles (VLP), which could also strongly activate the immune system. However, these VLPs assembled poorly and did not have the same structure as infectious HPV. In 1993, a laboratory at the US National Cancer Institute was able to generate HPV16 VLPs that were morphologically correct. These VLPs were the basis for the HPV16 component of the Gardasil vaccine. Upon commercialization of the vaccine, disputes involving intellectual property ownership arose between the various groups that had played a role in its development.
Merck & Co. conducted a Phase III study named Females United to Unilaterally Reduce Endo/Ectocervical Disease (FUTURE II). This clinical trial was a randomized double-blind study with one controlled placebo group and one vaccination group. Over 12,000 women aged 16–26 from thirteen countries participated in the study. Each woman was injected with either Gardasil or a placebo on day 1, month 2, and month 6. In total, 6,082 women were given Gardasil and 6,075 received the placebo. Subjects in the vaccine group had a significantly lower occurrence of high-grade cervical intraepithelial neoplasia related to HPV-16 or HPV-18 than did those in the placebo group. On February 27, 2006, the independent Data and Safety Monitoring Board recommended the clinical trials be terminated on ethical grounds, so that young women on placebo could receive Gardasil. Merck tested the vaccine in several hundred 11- and 12-year-old girls.
Indications and prevalence
Gardasil is a prophylactic HPV vaccine, meaning that it is designed to prevent HPV infections. For maximum effect, it is recommended that girls receive the vaccine prior to becoming sexually active. However, women who were already infected with one or more of the four HPV types targeted by the vaccine (6, 11, 16, or 18) were protected from clinical disease caused by the remaining HPV types in the vaccine.
Since Gardasil will not block infection with all of the HPV types that can cause cervical cancer, the vaccine should not be considered a substitute for routine pap smears.
Fewer HPV infections mean fewer complications from the virus and less time and money spent on the detection, work-up, and treatment of cervical cancer and its precursor, cervical dysplasia. It prevents infertility caused by cervical biopsies and reduces the severe respiratory problems of children who are infected by HPV from their mothers.
In addition, protection against HPV 6 and HPV 11 is expected to eliminate 90% of the cases of genital warts. Gardasil also protects against vulvar and vaginal cancers caused by HPV types 16 and 18.
In December 2010, Gardasil was approved by the FDA for prevention of anal cancer and associated precancerous lesions due to human papillomavirus (HPV) types 6, 11, 16, and 18 in people ages 9 through 26 years.
HPV infections, especially HPV 16, contribute to some head and neck cancer (HPV is found in an estimated 26-35% of head and neck squamous cell carcinoma). In principle, HPV vaccines may help reduce incidence of such cancers caused by HPV, but this has not been demonstrated.
Merck was denied FDA approval to market Gardasil to women aged 27 to 45. Although it was found to be safe and effective in the prevention of genital warts, it was not effective in the prevention of cervical cancer in that age group. This is because HPV rates rise quickly during teenage years and early twenties, but the chances decrease as people reach ages past their early twenties.
Use in males
Gardasil is also effective in males, providing protection against genital warts, anal cancer, and some potentially precancerous lesions caused by some HPV types. An ongoing study of 4,065 males demonstrated the efficacy of Gardasil in males who did not have HPV infection prior to vaccination. The vaccination is expected to protect against penile cancer and anal cancer caused by included HPV types, and research in this area is ongoing. Gardasil vaccine has been shown to significantly decrease the risk of young men contracting genital warts. In the United States the U.S. Food and Drug Administration (FDA) approved administration of the vaccine to males between ages 9 and 26 in October 2009. In the UK, HPV vaccines are licensed for males aged 9 to 15 and for females aged 9 to 26.
Men who have sex with men (MSM) are particularly at risk for conditions associated with HPV types 6, 11, 16, and 18; diseases and cancers that have a higher incidence among MSM include anal intraepithelial neoplasias, anal cancers, and genital warts. Type 16 is also associated with oropharyngeal squamous-cell carcinoma, a form of throat cancer. A 2005 study in San Francisco found that 95% of HIV-infected gay men also had anal HPV infection, of which 50% had precancerous HPV-caused lesions.
Gardasil is given in three 0.5 milliliter injections over six months. The second injection is two months after the first, and the third injection is six months after the first shot was administered.
- Major capsid protein L1 of HPV types 6, 11, 16, and 18
- amorphous aluminum hydroxyphosphate sulfate (adjuvant)
- yeast protein
- sodium chloride
- polysorbate 80
- sodium borate
The HPV major capsid protein, L1, can spontaneously self-assemble into virus-like particles (VLPs) that resemble authentic HPV virions. Gardasil contains recombinant VLPs assembled from the L1 proteins of HPV types 6, 11, 16 and 18. Since VLPs lack the viral DNA, they cannot induce cancer. They do, however, trigger an antibody response that protects vaccine recipients from becoming infected with the HPV types represented in the vaccine. The L1 proteins are produced by separate fermentations in recombinant Saccharomyces cerevisiae and self-assembled into VLPs.
The National Cancer Institute says, "[Gardasil and Cervarix] have been shown to provide protection against persistent cervical HPV 16/18 infections for up to 8 years, which is the maximum time of research follow-up thus far...HPV vaccination has also been found to prevent nearly 100 percent of the precancerous cervical cell changes that would have been caused by HPV 16/18. The data so far show duration of production for up to 6.4 years with Cervarix and for up to 5 years for Gardasil—in women who were not infected with HPV at the time of vaccination."
Gardasil has been shown to be partially effective (approximately 38%) in preventing cervical cancer caused by ten other high-risk HPV types.
Antibody levels at month 3 (1 month postdose 2) are substantially higher than at month 24 (18 months postdose 3), suggesting that protection is achieved by month 3 and perhaps earlier. This does not imply that the third dose can be skipped. One study has shown that Cervarix may be effective with fewer than three doses, but the result may not apply to Gardasil and further study is needed.
As of April 2014[update], more than 170 million doses of Gardasil had been distributed worldwide. The vaccine was tested in thousands of females (ages 9 to 26). The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) consider the vaccine to be safe. It does not contain mercury, thiomersal, live viruses or dead viruses, but virus-like particles, which cannot reproduce in the human body.
Publications of FDA and the CDC state that the vaccine has mostly minor side effects, such as soreness around the injection area. Fainting is more common among adolescents receiving the Gardasil vaccine than in other kinds of vaccinations. Patients should remain seated for 15 minutes after they receive the HPV vaccine. There have been reports that the shot is more painful than other common vaccines, and the manufacturer Merck partly attributes this to the virus-like particles within the vaccine. General side effects of the shot may include joint and muscle pain, fatigue, physical weakness and general malaise.
An update on adverse events was published by the Journal of the American Medical Association and looked at data from the Vaccine Adverse Event Reporting System (VAERS), covering 12,424 reported adverse events after about 23 million doses of vaccine between June 2006 and December 2008. Most adverse effects were minor and not greater than background rates compared with other vaccines, the exception being higher rates for syncope and venous thromboembolic events. Venous thromboembolic events were noted in 56 reports at a rate of 0.2 cases per 100,000 doses distributed and included 19 cases of pulmonary embolism, four of which were fatal. Overall, 772 events (6.2% of the total number of adverse events but only 0.003% of the total number of doses) were described as serious and included 32 reported deaths (1 per 1,000,000 doses).
Other adverse events include local site reactions (7.5 cases per 100,000 doses distributed), headaches (4.1 cases per 100,000 doses distributed), hypersensitivity reactions (3.1 cases per 100,000 doses distributed), and urticaria (hives) (2.6 cases per 100,000 doses distributed). A Kaiser Permanente study tracking 190,000 girls and women post-vaccination for two years found that rates of the autoimmune disorders lupus, rheumatoid arthritis, juvenile rheumatoid arthritis, idiopathic thrombocytopenic purpura (ITP), hemolytic anemia, multiple sclerosis, thyroiditis and type 1 diabetes mellitus in vaccinated populations were the same as in unvaccinated populations.
The FDA and the CDC said that with millions of vaccinations "by chance alone some serious adverse effects and deaths" will occur in the time period following vaccination, but they have nothing to do with the vaccine. More than twenty women who received the Gardasil vaccine have died, but these deaths have not been causally connected to the shot. Where information has been available, the cause of death was explained by other factors. Likewise, a small number of cases of Guillain-Barré Syndrome (GBS) have been reported following vaccination with Gardasil, though there is no evidence linking GBS to the vaccine. It is unknown why a person develops GBS, or what initiates the disease.
The FDA and the CDC monitor events to see if there are patterns, or more serious events than would be expected from chance alone. The majority (68%) of side effects data were reported by the manufacturer, but in about 90% of the manufacturer reported events, no follow-up information was given that would be useful to investigate the event further. In February 2009, the Spanish ministry of health suspended use of one batch of Gardasil after health authorities in the Valencia region reported that two girls had become ill after receiving the injection. Merck has stated that there was no evidence Gardasil was responsible for the two illnesses.
Public health advantages
The National Cancer Institute writes:
- Widespread vaccination has the potential to reduce cervical cancer deaths around the world by as much as two-thirds, if all women were to take the vaccine and if protection turns out to be long-term. In addition, the vaccines can reduce the need for medical care, biopsies, and invasive procedures associated with the follow-up from abnormal Pap tests, thus helping to reduce health care costs and anxieties related to abnormal Pap tests and follow-up procedures.
Long-term impact and cost-effectiveness
|This article is outdated. (July 2009)|
One unknown property of the vaccines now being researched is the persistence of their protective effects. Since the Gardasil vaccine has been administered for only a few years now, it is unknown whether it will provide lifelong immunity to recipients. In coming decades, further study will answer this question.
Whether the effects are temporary or lifelong, widespread vaccination could have a substantial public health impact. 270,000 women died of cervical cancer worldwide in 2002. Acting FDA Administrator Andrew von Eschenbach said the vaccine will have "a dramatic effect" on the health of women around the world. Even in the United States, where screening programs are routine, the National Cancer Institute estimated that 9,700 women would develop cervical cancer in 2006, and 3,700 would die.
Merck and CSL Limited are expected to market Gardasil as a cancer vaccine, rather than an STD vaccine. It remains unclear how widespread the use of the three-shot series will be, in part because of its $525 list price ($175 each for three shots).
Studies using different pharmacoeconomic models predict that vaccinating young women with Gardasil in combination with screening programs may be more cost effective than screening alone. These results have been important in decisions by many countries to start vaccination programs. For example, the Canadian government approved $300 million to buy the HPV vaccine in 2008 after deciding from studies that the vaccine would be cost-effective especially by immunizing young women. Marc Steben, an investigator for the vaccine, wrote that the financial burden of HPV related cancers on the Canadian people was already $300 million per year in 2005, so the vaccine could reduce this burden and be cost-effective.
Since penile and anal cancers are much less common than cervical cancer, HPV vaccination of young men is likely to be much less cost-effective than for young women.
Diane Harper, an HPV researcher who worked on studies that resulted in the vaccine being approved, called for more complete warnings for parents and questions its risk-versus-benefit profile because it is not yet known how long the vaccine will be effective once administered. The August 2009 issue of the Journal of the American Medical Association had an article reiterating the safety of Gardasil and another questioning the way it was presented to doctors and parents.
The new vaccine against 4 types of human papillomavirus (HPV), Gardasil, like other immunizations appears to be a cost-effective intervention with the potential to enhance both adolescent health and the quality of their adult lives. However, the messages and the methods by which the vaccine was marketed present important challenges to physician practice and medical professionalism. By making the vaccine's target disease cervical cancer, the sexual transmission of HPV was minimized, the threat of cervical cancer to adolescents was maximized, and the subpopulations most at risk practically ignored. The vaccine manufacturer also provided educational grants to professional medical associations (PMAs) concerned with adolescent and women's health and oncology. The funding encouraged many PMAs to create educational programs and product-specific speakers' bureaus to promote vaccine use. However, much of the material did not address the full complexity of the issues surrounding the vaccine and did not provide balanced recommendations on risks and benefits. As important and appropriate as it is for PMAs to advocate for vaccination as a public good, their recommendations must be consistent with appropriate and cost-effective use.
Political and other controversy
Anti-vaccination and parental groups protested the use of the vaccine after it was revealed the producer of Gardasil, Merck & Co., was lobbying state legislatures to introduce compulsory vaccination against HPV for preteen girls as a requirement for school attendance. Some objections were due to the vaccine protecting against a sexually transmitted disease, human papillomavirus, the primary causative agent of cervical cancer. The vaccine was contrasted to other mandated vaccines that are typically for diseases spread through casual contact, such as measles and mumps. On February 20, 2007, Merck announced its immediate suspension of this campaign, saying, "We're concerned that our role in supporting school requirements is a distraction from that goal (providing women with a vaccine for HPV), and as such have suspended our lobbying efforts."
The governor of Texas, Rick Perry, issued an executive order adding Gardasil to the state's required vaccination list, which was later overturned by the Texas legislature. Perry has also allowed parents to opt out of the program more easily. Through lobbying efforts, Merck has suggested that governments make vaccination with Gardasil mandatory for school attendance, which has upset some conservative groups and libertarian groups. Conservative groups, including the Family Research Council (FRC), have expressed fear that vaccination with Gardasil might give girls a false sense of security regarding sex and lead to promiscuity, but no evidence exists to suggest that girls who were vaccinated later engaged in more sexual activity than unvaccinated girls. Perry's decision was later criticized on September 12, 2011 by fellow presidential candidates Ron Paul and Michele Bachmann during the Republican Party presidential debate as being an overreach of state power in a decision properly left to parents.
In July 2006, the developments by Merck & Co had led to Gardasil being introduced to Canada. The vaccine was developed to prevent the HPV types 6, 11, 16, and 18 from infecting those who are sexually active. The need for the vaccine in Canada was a result of HPV being one of the most frequently occurring sexually transmitted diseases in the country. However, the way the government and pharmaceutical companies went about campaigning the vaccine throughout the country proved to be problematic. As a result of the target audience for the vaccine being females between the ages of 9-26, the Canadian government turned to the school system to administer the vaccine. The Canadian Federal government used $300 million in three years to help administer the vaccine throughout schools. In 2007 the provincial school-based programs used the money to vaccinate school age children. In 2007 debates among the public became prominent as a result of the provincial governments targeting children in grade 8 for the vaccine. The debates became controversial because of the age range used to be immunized and because at the time the vaccine was starting to be used, there was no long-term data provided from clinical trials. Issues also arose from the campaigns used for the vaccine because the young females being vaccinated were not taken into consideration in regards to how they felt about being vaccinated.
In June 2013, the Japanese government issued a notice that "cervical cancer vaccinations should no longer be recommended for girls aged 12 to 16." The vaccines sold in Japan are Cervarix, made by GlaxoSmithKlein PLC of Britain, and Gardasil, made by Merck Sharp & Dohme. An estimated 3.28 million people have received the vaccination; 1,968 cases of possible side effects have been reported.
This is the second time the Japanese government has suspended a vaccine. An analysis of the drugs found 245.1 reports of side effects per million vaccinations for Cervarix and 155.7 reports per million for Gardasil. There were two other vaccines analyzed concurrently; reports of those side effects were 89.1 per million for pneumococcus vaccines and 67.4 per million for Japanese encephalitis vaccines.
- "Silgard European Public Assessment Report". European Medicines Agency. September 25, 2009. Retrieved 2009-12-05.
- Waknine, Yael (October 2, 2006). "International Approvals: Singulair and Gardasil/Silgard". Medscape Today. Retrieved 2008-12-18.
- Richwine, Lisa (August 20, 2009). "UPDATE 2-U.S. health officials back safety of Merck vaccine". Reuters. Retrieved 2009-11-12.
- Markowitz, L. E.; Dunne, E. F.; Saraiya, M.; Lawson, H. W.; Chesson, H.; Unger, E. R.; Centers for Disease Control Prevention (CDC); Advisory Committee on Immunization Practices (ACIP) (2007). "Quadrivalent Human Papillomavirus Vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP)". MMWR. Recommendations and reports : Morbidity and mortality weekly report. Recommendations and reports / Centers for Disease Control 56 (RR-2): 1–24. PMID 17380109.
- Centers for Disease Control and Prevention (CDC) (2010). "FDA licensure of quadrivalent human papillomavirus vaccine (HPV4, Gardasil) for use in males and guidance from the Advisory Committee on Immunization Practices (ACIP)". MMWR. Morbidity and mortality weekly report 59 (20): 630–632. PMID 20508594.
- Lowy DR, Schiller JT (May 2006). "Prophylactic human papillomavirus vaccines". J. Clin. Invest. 116 (5): 1167–73. doi:10.1172/JCI28607. PMC 1451224. PMID 16670757. Retrieved 2009-11-12.
- Muñoz N, Bosch FX, Castellsagué X (August 2004). "Against which human papillomavirus types shall we vaccinate and screen? The international perspective". Int. J. Cancer 111 (2): 278–85. doi:10.1002/ijc.20244. PMID 15197783.
- Cortez, Michelle Fay; Pettypiece, Shannon (13 November 2008). "Merck Cancer Shot Cuts Genital Warts, Lesions in Men (Update2)". Bloomberg News. Retrieved 2009-11-12.
- "FDA Approves Expanded Uses for Gardasil to Include Preventing Certain Vulvar and Vaginal Cancers" (Press release). U.S. Food and Drug Administration (FDA). 2008-09-12. Retrieved 2009-11-11.
- "The Ethics of Vaccination". Springer Publishing Company. Retrieved September 29, 2013.
- "The Ethics of vaccination". Springer Publishing Company. Retrieved October 3, 2013.
- Haupt, Richard; Sings, Heather (November 2011). "The efficacy and safety of the quadrivalent human papillomavirus 6/11/16/18 vaccine gardasil". Journal of Adolescent Health 49 (5): 467–475. doi:10.1016/jodohealth.2011.07.003. PMID 22018560.
- "Gardasil full prescribing information". Merck & Co. Retrieved 2009-11-11.
- "Gardasil Vaccine Safety". Vaccine Safety & Availability. U.S. Food and Drug Administration (FDA). August 20, 2009. Retrieved 2009-11-11.
- McNeil C (April 2006). "Who invented the VLP cervical cancer vaccines?". J. Natl. Cancer Inst. 98 (7): 433. doi:10.1093/jnci/djj144. PMID 16595773. Retrieved 2009-11-11.
- The FUTURE II Study Group (May 2007). "Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions". The New England Journal of Medicine 356 (19): 1915–27. doi:10.1056/NEJMoa061741. PMID 17494925. Retrieved 2009-11-11.
- Roberts, J (2007-02-27). "Gardasil Trials End on Tuesday Due To Success". Vaccine Rx. Archived from the original on September 28, 2007. Retrieved 2007-02-27.
- "Gardasil Efficacy Questioned by Experts says Wall Street Journal". Vaccine Rx. 2007-04-16. Archived from the original on September 28, 2007. Retrieved 2007-04-16.
- "FDA: Gardasil approved to prevent anal cancer" (Press release). U.S. Food and Drug Administration (FDA). December 22, 2010. Retrieved 2011-01-04.
- "New England Journal of Medicine Publishes Efficacy and Safety Data for Gardasil in Males" (Press release). Merck & Co. February 2, 2011. Retrieved 2011-02-12.
- Goon PK, Stanley MA, Ebmeyer J (October 2009). "HPV & head and neck cancer: a descriptive update". Head Neck Oncol 1 (1): 36. doi:10.1186/1758-3284-1-36. PMC 2770444. PMID 19828033. Retrieved 2009-11-11.
- Vousden, K.H. (1994). "Cell transformation by human papillomaviruses". Viruses and Cancer (New York: Press Syndicate of the University of Cambridge). pp. 27–46. ISBN 9780521454728.
- Masters, Coco (May 11, 2007). "Oral Sex Can Add to HPV Cancer Risk". Time.
- Vousden, K.H. (1994). Viruses and Cancer. New York: Press Syndicate of the University of Cambridge. p. 27. ISBN 0521454727.
- "U.S. Prescribing Information for GARDASIL® Updated; Indication Not Granted for Use in Adult Women". Retrieved 31 July 2011.
- Giuliano, AR; Palefsky, JM; Goldstone, S; Moreira, ED; Penny, ME; Aranda, C; Vardas, E; Moi, H et al. (February 2011). "Efficacy of quadrivalent HPV vaccine against HPV Infection and disease in males". N. Engl. J. Med. 364 (5): 401–11. doi:10.1056/NEJMoa0909537. PMC 3495065. PMID 21288094. Lay summary.
- "Gardasil, Merck's Cervical Cancer Vaccine, Demonstrated Efficacy in Preventing HPV-Related Disease in Males in Phase III Study: Pivotal Study Evaluating Efficacy of Gardasil in Males in Preventing HPV 6, 11, 16 and 18-Related External Genital Lesions" (Press release). Merck & Co. November 13, 2008. Retrieved 2009-12-05.
- "Gay men seeking HPV vaccine". Cancer Research UK. 23 February 2007. Retrieved 2009-11-12.
- "FDA Approves New Indication for Gardasil to Prevent Genital Warts in Men and Boys" (Press release). U.S. Food and Drug Administration (FDA). 2009-10-16. Retrieved 2009-11-12.
- "October 16, 2009 Approval Letter - Gardasil". U.S. Food and Drug Administration (FDA). October 16, 2009. Retrieved 2009-11-12.
- "FDA Approves Gardasil for Use in Boys and Young Men" (Press release). Merck & Co. October 16, 2009. Retrieved 2009-11-12.
- Roberts, Michelle (2007-02-23). "Gay men seek 'female cancer' jab". BBC News. Retrieved 2009-11-12.
- D'Souza, G; Kreimer, AR; Viscidi, R; Pawlita, M; Fakhry, C; Koch, WM; Westra, WH; Gillison, ML (May 10, 2007). "Case-control study of human papillomavirus and oropharyngeal cancer". N Engl J Med 356 (19): 1944–56. doi:10.1056/NEJMoa065497. ISSN 0028-4793. PMID 17494927.
- Edwin J. Bernard (August 29, 2005). "HAART is not reducing risk of anal cancer in gay men". AIDSmap. Retrieved 2006-06-08.
- "Gardasil Patient Product Information". Merck & Co. Retrieved 2009-11-11.
- Merck Canada Inc. "Gardasil Product Monograph". Retrieved 20 February 2013.
- "Human Papillomavirus (HPV) Vaccines". National Cancer Institute (NCI). 2009-10-22. Retrieved 2009-11-11.
- Schieszer, John (November 2007). "HPV Vaccine Protects Against 10 "Other" Strains". Internal Medicine World Report.
- Block, SL; Nolan, T, Sattler, C, Barr, E, Giacoletti, KE, Marchant, CD, Castellsagué, X, Rusche, SA, Lukac, S, Bryan, JT, Cavanaugh PF, Jr, Reisinger, KS, Protocol 016 Study, Group (November 2006). "Comparison of the immunogenicity and reactogenicity of a prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in male and female adolescents and young adult women.". Pediatrics 118 (5): 2135–45. doi:10.1542/peds.2006-0461. PMID 17079588.
- Kreimer, A. R.; Rodriguez, A. C., Hildesheim, A., Herrero, R., Porras, C., Schiffman, M., Gonzalez, P., Solomon, D., Jimenez, S., Schiller, J. T., Lowy, D. R., Quint, W., Sherman, M. E., Schussler, J., Wacholder, S. (9 September 2011). "Proof-of-Principle Evaluation of the Efficacy of Fewer Than Three Doses of a Bivalent HPV16/18 Vaccine". JNCI Journal of the National Cancer Institute 103 (19): 1444–1451. doi:10.1093/jnci/djr319.
- Donald G McNeil Jr for the New York Times. March 31, 2014 Expansion in Use Of Cancer Vaccine
- "HPV Vaccine Information For Young Women". Centers for Disease Control and Prevention (CDC). Retrieved 2009-06-14.
- Mike Stobbe (January 3, 2008). "Cervical cancer shots are gaining reputation as painful". ABC News. Associated Press.
- Amy Fagan (10 July 2008). "Merck, FDA expand Gardasil warnings". The Washington Times.
- Slade, B. A.; Leidel, L.; Vellozzi, C.; Woo, E. J.; Hua, W.; Sutherland, A.; Izurieta, H. S.; Ball, R.; Miller, N.; Braun, M. M.; Markowitz, L. E.; Iskander, J. (August 2009). "Postlicensure Safety Surveillance for Quadrivalent Human Papillomavirus Recombinant Vaccine". Journal of the American Medical Association 302 (7): 750–757. doi:10.1001/jama.2009.1201. PMID 19690307.
- Chustecka Z (August 18, 2009). "HPV Vaccine: Debate Over Benefits, Marketing, and New Adverse Event Data". Medscape Today. Retrieved August 27, 2009.
- Hernandez-Millett, S.; Schwartz, E. (January 15, 2012). "Kaiser Permanente Study Finds Gardasil does not Trigger Lupus, Rheumatoid Arthritis or Type 1 Diabetes after Vaccination" (Press release). Pasadena, California: Kaiser Permanente. Retrieved June 18, 2013.
- Chao, C.; Klein, N. P.; Velicer, C. M.; Sy, L. S.; Slezak, J. M.; Takhar, H.; Ackerson, B.; Cheetham, T. C.; Hansen, J.; Deosaransingh, K.; Emery, M.; Liaw, K. -L.; Jacobsen, S. J. (2012). "Surveillance of autoimmune conditions following routine use of quadrivalent human papillomavirus vaccine". Journal of Internal Medicine 271 (2): 193–203. doi:10.1111/j.1365-2796.2011.02467.x. PMID 21973261.
- Rosenthal, Elisabeth (2008-08-19). "Drug Makers' Push Leads to Cancer Vaccines' Fast Rise". The New York Times. Retrieved 2008-08-20.
- "Information from FDA and CDC on Gardasil and its Safety (Archived)". Centers for Disease Control and Prevention (CDC). July 22, 2008.
- "Reports of Health Concerns Following HPV Vaccination". Centers for Disease Control and Prevention (CDC). October 26, 2010.
- "HPV Vaccine - Questions & Answers for the Public". 2008-07-18. Archived from the original on 2008-03-06. Retrieved 2008-08-22.
- "Guillain-Barré Syndrome Fact Sheet". National Institute of Neurological Disorders and Stroke (NINDS). May 6, 2010.
- "Spain halts batch of Merck's Gardasil". Reuters. February 10, 2009. Retrieved 2009-02-10.
- Cohen, J (April 2005). "PUBLIC HEALTH: High hopes and dilemmas for a cervical cancer vaccine". Science 308 (5722): 618–21. doi:10.1126/science.308.5722.618. PMID 15860602.
- "FDA approves first vaccine for cervical cancer". msnbc.com. Associated Press. June 16, 2006. Retrieved June 8, 2006.
- SEER Stat Fact Sheets: Cervix Uteri. National Cancer Institute. Retrieved 30 March 2007.
- "Health Blue Book". Retrieved 15 August 2012.
- "HPV Vaccine Studied For First Time In Men". Science Daily. November 26, 2004.
- Stanley M (November 2007). "Prevention strategies against the human papillomavirus: the effectiveness of vaccination". Gynecol. Oncol. 107 (2 Suppl 1): S19–23. doi:10.1016/j.ygyno.2007.07.068. PMID 17938013.
- Pallecaros A, Vonau B (December 2007). "Human papilloma virus vaccine--more than a vaccine". Curr. Opin. Obstet. Gynecol. 19 (6): 541–6. doi:10.1097/GCO.0b013e3282f1a91b. PMID 18007131.
- Morris SK, Nguyen CK (2008). "The human papillomavirus vaccine in Canada". Can J Public Health 99 (2): 114–6. PMID 18457284.
- Steben M (March 2008). "Rebuttal: Do you approve of spending $300 million on HPV vaccination?: YES". Can Fam Physician 54 (3): 342, 344. PMC 2278341. PMID 18337521.
- Knox, Richard (September 19, 2011). "HPV Vaccine: The Science Behind The Controversy". National Public Radio. Retrieved 15 April 2014.
- Attkisson, Sharyl (August 19, 2009). "Gardasil Researcher Speaks Out". CBS News. Retrieved 2009-11-12.
- Rothman SM, Rothman DJ (August 2009). "Marketing HPV vaccine: implications for adolescent health and medical professionalism". JAMA 302 (7): 781–6. doi:10.1001/jama.2009.1179. PMID 19690311. Retrieved 2009-11-11.
- Linda A. Johnson (February 21, 2007). "Merck Suspends Lobbying for Vaccine". The Washington Post. Associated Press.
- Houppert, Karen (March 26, 2007). "Who's Afraid of Gardasil?". The Nation. Retrieved 2009-11-11.
- Danny Fortson (11 June 2006). "Moral majority take on GSK and Merck over cancer drugs". The Independent. Retrieved June 12, 2006.
- Barillas, Martin (2006-09-14). "Gardasil vaccine touted in Michigan". Spero News. Retrieved 2007-01-26.
- Gaul, Moira (2007). "Gardasil: What Parents should know about the new HPV vaccine". Family Research Council. Retrieved 2011-09-13.
- Bednarczyk, R. A.; Davis, R.; Ault, K.; Orenstein, W.; Omer, S. B. (2012). "Sexual activity-related outcomes after human papillomavirus vaccination of 11- to 12-year-olds.". Pediatrics 130 (5): 798–805. doi:10.1542/peds.2012-1516. PMID 23071201.
- Gabriel, Trip; Denise Grady (2011-09-13). "In Republican Race, a Heated Battle Over the HPV Vaccine". New York Times. Retrieved 2011-09-14.
- Japan Times. (16 June 2013). "Cervix vaccine issues trigger health notice." Accessed 9 July 2013.
- The Asahi Shimbun. (15 June 2013). "Health ministry withdraws recommendation for cervical cancer vaccine." Accessed 9 July 2013.
- Official website
- Silgard EPAR summary for the public
- Shi, L; Sings, HL; Bryan, JT; Wang, B; Wang, Y; Mach, H; Kosinski, M; Washabaugh, MW; Sitrin, R; Barr, E (February 2007). "Gardasil: prophylactic human papillomavirus vaccine development – from bench top to bed-side". Clinical Pharmacology & Therapeutics 81 (2): 259–64. doi:10.1038/sj.clpt.6100055. ISSN 0009-9236.
- Ireland, Corydon (2006). "A Cancer Vaccine is Born". Rochester Review (University of Rochester) 68 (3).
- Harris, Gardiner (30 June 2006). "Panel Unanimously Recommends Cervical Cancer Vaccine for Girls 11 and Up". The New York Times.
- Product Approval Information U.S. Food and Drug Administration (FDA)
- Hellerstein, Myra; Thieroff, Amanda (1 February 2007). "HPV and You: Girls learn about HPV from the commercials, not the classroom". The Indypendent.
- McNeil, Donald G., Jr. (August 29, 2006). "How a Vaccine Search Ended in Triumph". The New York Times.