- What is human papillomavirus? The human papilloma virus (HPV) or human papillomavirus, are a group of over 100 related viruses. They are called papillomaviruses because certain of its types can cause warts, or papillomas, which are benign (not cancerous). The papillomaviruses that cause common warts that grow on hands and feet are different from those that cause tumors in the throat or genital area. Some types of HPV are associated with certain types of cancer. They are called human papillomavirus oncogenic or cancer-causing "high risk."
Among the more than 100 types of HPV, over 30 can be passed from one person to another through sexual contact. Transmission can occur in the region the genitals, anus or mouth. Although HPVs are usually transmitted sexually, doctors can not say for certain when infection occurred. Almost 6 million new genital HPV infections occur each year in the United States. Most HPV infections occur without symptoms and go away without any treatment over the course of a few years. However, sometimes HPV infection persists for many years, causing or anomalies that can be detected in cells.
- do they cause cancer infections with human papilloma virus? Infection by certain types of HPV is the main cause of cervical cancer (cervix). Almost all women will be infected with HPV at some point in their lives, but very few will develop cervical cancer. The immune system of most women will usually suppress or eliminate HPV. Only HPV infections are persistent (do not go away over many years) can lead to cervical cancer. In 2009, more than 11 000 women in the United States will be diagnosed with this type of cancer and nearly 4 000 will die from it. Cervical cancer affects nearly 500 000 women a year worldwide, claiming more than 250 000 lives. Studies have found that HPV infection is a major risk factor for oropharyngeal cancer (cancer that forms in tissues of the oropharynx, which is the central part of the throat and includes the soft palate, tongue base and tonsils) (1 , 2). Studies also suggest that HPVs may play a role in cancers of the anus, vulva, vagina and penis.
- Can HPV infection be prevented? The surest way to eliminate the risk of genital HPV infection is to refrain from any genital contact with another person. For those who choose
be sexually active, a mutually monogamous relationship in the long term with an uninfected partner is the strategy most likely to prevent genital HPV infection. However, it is difficult to determine whether a person who has been sexually active in the past is currently infected.
not known how much protection provided by condoms (condoms) against HPV infection, because areas not covered by the condom can be infected by the virus. Although it is unknown the effect of condoms in preventing HPV infection, its use has been associated with a lower rate of cervical cancer, HPV-associated disease.
Management Food and Drug U.S. (Food and Drug Administration , FDA) has approved two vaccines to prevent infection with HPV: Gardasil ® and Cervarix ®. Both vaccines are highly effective in preventing persistent infection with HPV types 16 and 18 of HPV, two of the HPV "high risk" that cause most (70%) of cervical cancers. Gardasil also prevents infection with types 6 and 11 of HPV, which cause virtually all (90%) genital warts (3 ). In addition, there are initial data suggest that Cervarix partially protects against some other types of HPV that can cause cancer. However, further studies are needed to understand the impact and magnitude of this effect.
- "What are Gardasil and Cervarix? The vaccine Gardasil, made by Merck & Co., Inc. (Merck), is said to be a quadrivalent vaccine because it protects against four HPV types 6, 11, 16 and 18. Gardasil is administered in a series of three injections into muscle tissue for a period of 6 months. Gardasil was approved by the FDA for use in women to prevent cervical cancer and some vulvar and vaginal cancers caused by types 16 and 18 of HPV, so, too, was approved for use in men and women for the prevention of genital warts caused by HPV types 6 and 11 HPV. The vaccine has been approved for such use in men and women 9 to 26 years of age.
Cervarix is \u200b\u200bproduced by GlaxoSmithKline (GSK). This vaccine is said to be bivalent because it targets two HPV types 16 and 18. Also given in three doses over a period of 6 months. The FDA has approved Cervarix for use in women aged 10 to 25 years of age to prevent cervical cancer caused by types 16 and 18 of HPV.
Both vaccines are based on technology developed in part by scientists at the National Cancer Institute (NCI). NCI, part of the National Institutes Health (NIH), has licensed this technology to two pharmaceutical companies, Merck and GSK, to produce the HPV vaccine for general distribution.
There is no evidence that any of these two HPV vaccines provide complete protection against persistent infection with other HPV types, although there are initial data suggest that both vaccines could provide partial protection against a few other types of HPV that can cause cervical cancer. In general, therefore, about 30% of cases of cervical cancer can not be prevented by these vaccines. Also, in the case of Gardasil, 10% of cases of genital warts be prevented with this vaccine. Neither vaccine prevents sexually transmitted diseases or treat HPV infection or cervical cancer.
Because the vaccines do not protect against all infections that cause cervical cancer, it is important that women receive the vaccine continue making screening for cervical cancer, as recommended for women have not been vaccinated.
- How HPV vaccines work? The HPV vaccine works like other vaccines that protect against viral infections. The researchers hypothesized that surface components unique to HPV could create an antibody response capable of protecting the body against infection and that these components could be used to form the basis of a vaccine. These surface components can act together to form virus-like particles ( virus-like particles, VLP ) that are not infectious and stimulating the immune system to produce antibodies that can prevent complete papillomavirus infected cells. Are thought to protect primarily by causing the production of antibodies that prevent infection and, consequently, the formation of cervical cell changes (as seen in Pap tests) that can lead to cancer (4 ). Although these vaccines can help prevent HPV infection, not help to eliminate HPV infection already present.
- How effective are the vaccines against HPV? Gardasil and Cervarix are highly effective in preventing infection of HPV types to which they are addressed. Studies have shown that both Gardasil and Cervarix prevented nearly 100% of precancerous changes in cervical cells caused by HPV types the vaccine targets that up to 4 years after vaccination in women who were not infected at the time of vaccination (5 - 7).
- Why are these vaccines important? Widespread vaccination has the potential to reduce up to two thirds the number of deaths from cervical cancer in the world, if all women get the vaccine and if protection turns out to be long term. In addition, vaccines can reduce the need for medical care, biopsies and invasive procedures associated with the consequences of abnormal Pap tests, which help reduce health care costs and anxieties related to abnormal Pap tests and procedures Monitoring (4 ).
- How safe are the vaccines against HPV? Before any vaccine, the FDA must ensure that safe and effective. Both Gardasil and Cervarix have been tested in thousands of people in the United States and many other countries. So far, there have been no serious side effects caused by vaccines. The most common problems have been a brief illness and other symptoms at the injection site. These problems are similar to those experienced with other vaccines routinely. Gardasil and Cervarix have not been tested enough during pregnancy, so it should not be used by pregnant women.
A safety review conducted recently by the FDA and the Centers for Disease Control and Prevention ( Centers for Disease Control and Prevention, CDC ) took into account the adverse side effects associated with vaccination of Gardasil system were reported to the Adverse Reactions to Vaccines since the adoption of the vaccine ( 8 ). The rates of adverse side effects of the patch were consistent with rates observed in safety studies conducted before the adoption of the vaccine and were similar to rates that were observed with other vaccines. However, there was a higher proportion of syncope (fainting) and venous thrombotic events (blood clots) with Gardasil with other vaccines. Falls due to syncope can sometimes cause serious injuries, including head injuries can be avoided by ensuring that the person receiving the vaccine sit for 15 minutes after receiving the vaccine. The FDA and CDC have pointed to health care providers, to avoid falls and injuries, all people receiving the vaccine must remain seated or lying down and be monitored for 15 minutes after vaccination. You can get more information the CDC website at http://www.cdc.gov/vaccinesafety/Vaccines/HPV/hpv_faqs.html on the Internet.
- How long do the vaccines protect against infection? The duration of immunity is not yet known. Research is underway to determine how long protection will last. The phase III clinical studies have shown that Gardasil and Cervarix may offer protection against HPV16 for 4 years. Smaller studies suggested that protection may last more than 4 years, but it is unknown whether the protection afforded by vaccination last lifetime.
- "booster shots will be needed? Studies are needed to determine whether booster vaccinations (supplemental doses of a vaccine, usually less than the initial doses to be given to maintain immunity.)
- "Who should be vaccinated with these vaccines? has been shown that both Gardasil and Cervarix are only effective if given before HPV infection, so it is recommended to apply before the person becomes sexually active. The decision the FDA to grant the license includes information about age and gender of those receiving the vaccine. The FDA approved Gardasil for use in females 9 to 26 years of age and approved Cervarix for use in women 10 to 25 years. Merck
data show that Gardasil is highly effective in men in preventing genital warts caused by VPH11 VPH6 and the two types of HPV that cause most genital warts. The FDA approved Gardasil for use in males 9 to 26 years of age to prevent genital warts caused by VPH6 and VPH11.
addition to the benefits that exist for the prevention of cervical cancer in women and the prevention of warts both women and men, there may be additional benefits of vaccination, these are a reduction in the risk of cancer of the anus and oropharynx in men and women and penile cancer in men. However, clinical studies have not directly tested these possibilities.
After the FDA licenses the vaccine, the Advisory Committee on Immunization Practices ( Advisory Committee on Immunization Practices, ACIP ) makes additional recommendations to the Secretary of the Department of Health and Human Services ( Department of Health and Human Services, DHHS ) and director of the CDC about who should receive the vaccine, at what age, how often, the appropriate dose and situations that should not be administered. The committee is composed of 15 experts in fields related to immunization. The committee also advises on the most effective ways to use vaccines to prevent diseases. The committee recommended that Gardasil be administered routinely to girls 11 to 12 years. The recommendations also allow the vaccination of girls beginning at 9 years of age as well as vaccination of girls and women ages 13 to 26 years of age. Committee is expected to issue the policy on Cervarix in the coming months. It is also expected the committee makes recommendations on the use of the vaccine in men. The cost-effectiveness of vaccinating men is being discussed because HPV-associated cancers are less common in men than in women. You can learn more about the committee's recommendations for vaccination against HPV in the website of the Centers for Disease Control and Prevention in http://www.cdc.gov/mmwr/pdf/rr/rr5602 . pdf on the Internet.
addition, states can decide whether or not require vaccination of children before they enroll in school or childcare. Each state individually making this decision. The National Network for Immunization Information ( National Network for Immunization Information, NNii ) provides information on specific state decisions in a matter of vaccines on their website http://www.immunizationinfo.org/vaccines/state-requirements , Internet.
- "shall be administered the vaccine to people already infected with HPV? Although preventive vaccines currently under investigation have proved to be generally safe when given to women already infected with HPV, it is important that women know that vaccines protect against infection, and provide the best benefits, the woman who is vaccinated before being sexually active. This is because these vaccines do not treat infections. For example, the results of a recent study showed that Cervarix was not effective in helping cure the infection in women already infected with the virus (9 ). However, since very few young women have been infected with all HPV types in vaccines, it is possible that women still get residual benefits of vaccination even if they have been infected with one or more of the types in vaccines. This possibility has not been formally studied yet.
not feasible screening all women to determine who have been exposed to HPV types found in vaccines. Currently, there is no generally available test to see if a person has been exposed to HPV. The DNA test for HPV currently approved only shows whether a woman has a current HPV infection and identifies the type of HPV. Does not provide information on past infections. The decision to vaccinate or not, based on the possibility of previous exposure to these HPV types, is being discussed by the Advisory Committee on Immunization Practices and other advisory groups.
- "women should be vaccinated and have changes in cervical cells? Gardasil and Cervarix appear to be safe in women with cervical abnormalities, but no vaccine is expected to help clear these anomalies because it has been shown that the vaccine does not treat established infections. Women should talk with their healthcare providers about the treatment of abnormal changes in cervical cells.
- " need Pap tests done yet women have been vaccinated? Yes Because these vaccines do not protect against all HPV types that cause cancer, Pap tests and screening tests detection of cervical cancer are still essential to detect cervical cancers and precancerous changes. In addition, Pap tests are especially important for women who have not been vaccinated or who already have HPV infection.
- How much will these vaccines? Will insurance pay for them? The cost of Gardasil is $ 120 per dose and $ 360 for the entire series. Individual insurance plans or group are subject to state laws. These laws generally provide coverage based on the recommendations of the Advisory Committee on Immunization Practices. Medicaid coverage is defined according to the rules committee, and immunizations are a mandatory service under Medicaid for persons under age 21 who qualify. Medicaid also includes the Children's Vaccine Program ( Vaccines for Children Program). This program provides immunization services for children 18 and younger who qualify for Medicaid, uninsured, who have inadequate insurance and receive immunizations through a Federally Licensed Health Center or Rural Health Clinic, or are American Indians or Alaska Natives.
- " What research is being done on HPV? Researchers at the National Cancer Institute and elsewhere are studying how the types of high-risk HPV causes precancerous changes in normal cells and how they can prevent and manage these changes effectively. The NCI is doing in Costa Rica, where rates of cervical cancer are high, a clinical study of the HPV vaccine, Cervarix. This study is designed to obtain information about long-term safety of the vaccine, the extent and duration of protection on the immune mechanisms of protection and natural history of infection with HPV types not included in the vaccine. The NCI is also collaborating with other researchers in second-generation preventive vaccine and treatment for HPV vaccines, which would prevent the development of cancer in women previously infected with HPV. The ideal strategy would be a vaccine that combines in itself both preventive and therapeutic property.
Laboratory investigations indicated that HPVs produce proteins E5, E6 and E7. These proteins interfere with cellular functions that normally prevent excessive growth. For example, HPV E6 interferes with the human protein p53 which acts to prevent tumors from growing. By better understanding how these proteins interact, may help researchers devise ways to disrupt the process by which HPV infection can result in abnormal cell growth.
Researchers at the National Cancer Institute and elsewhere are also studying what people know and understand about HPV and cervical cancer, the best way to communicate to the public the most recent results of investigations, and how doctors talk with patients about HPV. This research will help to ensure that the public receives accurate information about HPV in an easy to understand and facilitate access to appropriate tests for those in need.
- "How can you learn more about HPV infection? Federal Government agencies can then provide more information about HPV infection: NCI
page that summarizes information about vaccines against human papilloma virus for cervical cancer provides links to NCI materials on vaccines HPV and general information about HPV, about cancer vaccines and cervical cancer and cervical cancer. This website English, is in http://www.cancer.gov/cancertopics/hpv-vaccines on the Internet.
The National Institute of Allergy and Infectious Diseases ( National Institute of Allergy and Infectious Diseases, NIAID), part of the National Institutes of Health, supports research on HPV infection and offers printed materials. To contact the NIAID:
Organization: National Institute of Allergy and Infectious Diseases Address: Office of Communications
and Government Relations 6610 Rockledge Drive, MSC 6612
Bethesda, MD 20892-6612
Phone: 301-496-5717 or 1-866-284-4107 (toll) TTY : 1-800-877-8339 Website: http://www.niaid.nih.gov
The website of the Prevention Division of Sexually Transmitted Diseases CDC also has information about HPV, including treatment guidelines and surveillance statistics. This website is in http://www.cdc.gov/std/English/STDFact-HPV-s.htm Internet. Selected Bibliography
- Division of STD Prevention. of genital HPV Infection Prevention and sequelae: Report of an external consultants' meeting . Centers for Disease Control and Prevention, 1999.
- D'Souza G, Kreimer AR, Viscidi R, et al. Case-control study of human papillomavirus and oropharyngeal cancer. New England Journal of Medicine 2007; 356(19):1944–1956.
- Koutsky LA, Ault KA, Wheeler CM, et al. A controlled trial of a human papillomavirus type 16 vaccine. New England Journal of Medicine 2002; 347(21):1645–1651.
- Steinbrook R. The potential of human papillomavirus vaccines. New England Journal of Medicine 2006; 354(11):1109–1112.
- Garland SM, Hernandez-Avila M, Wheeler CM, et al. Quadrivalent vaccine against human papillomavirus to prevent anogenital diseases. New England Journal of Medicine 2007; 356(19):1928–1943.
- The Future II Study Group. Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions. New England Journal of Medicine 2007; 356(19):1915–1927.
- Paavonen J, Naud P, Salmerón J, et al. Efficacy of human papillomavirus (HPV)–16/18 AS04-adjuvanted vaccine against cervical infection and precancer caused by oncogenic HPV types (PATRICIA): Final analysis of a double-blind, randomised study in young women. Lancet 2009; 274(9686):301–314.
- Slade BA, Leidel L, Vellozzi C, et al. Postlicensure safety surveillance for quadrivalent human papillomavirus recombinant vaccine. Journal of the American Medical Association 2009; 302(7):750–757.
- Hildesheim A, Herrero R, Wacholder S, et al. Effect of human papillomavirus 16/18 L1 viruslike particle vaccine among young women with preexisting infection: A randomized trial. Journal of the American Medical Association 2007; 298(7):743–753.