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What is genital HPV infection?
It is a sexually transmitted disease (STD) caused by the Human Papilloma Virus (HPV), a viral group that includes more than 100 different types. More than 30 are sexually transmitted and may affect the ano-genital area in both men and women. Most people infected by HPV have no symptoms and the infection disappears by itself.
However, some types of this virus are known as "high risk" and may show abnormal results in Papanicolaou tests (cervico-vaginal cytology). Other types of virus are known as "low risk" and may give rise to slight abnormalities in the Papanicolaou tests or cause genital warts.
- Consideraciones
El VPH se encuentra tan difundido que sólo las personas que no han tenido relaciones sexuales no han estado expuestas a él. En casi todos los casos la infección es subclínica y de corta duración. Los condones no previenen por completo la transmisión del VPH porque se puede contagiar durante las prácticas sexuales u otras actividades distintas al coito. Sin embargo, el riesgo se reduce con los condones. Los productos que se utilizan durante la menstruación también pueden transportar al virus. La inserción de los tampones puede trasladar al virus desde los labios hacia la vagina. Las compresas femeninas pueden retener y transmitir el virus. La humedad y la abrasión facilitan cualquier vía de transmisión. El coito anal es una forma de transmisión frecuente porque la mucosa anal es frágil y muy susceptible a la infección por VPH.
- What vaccines are available against HPV infection?
- Quadrivalent vaccine: recently approved by the USA Food and Drug Administration (FDA). It gives protection against four types of HPV: 6, 11, 16 and 18. It is administered in three injections over a period of 6 months.
- Bivalent vaccine: still undergoing trials; protects against two types of HPV: 16 and 18. It is also administered in three doses over a 6-month period. Both vaccines are based on a technology partly developed by scientists from the National Cancer Institute (NCI).
- How do anti-HPV vaccines work?
They work like other vaccines that protect against a viral infection. The unique surface components of HPV can create an antibody response capable of protecting the body against infection, and these components can be used as a basis for developing a vaccine.
- How effective are anti-HPV vaccines?
They are extremely effective for preventing infection by the specific types of HPV for which they have been devised. The vaccine approved by the FDA (Food and Drug Administration) provided protection against almost 100% of the precancerous changes in cervical cells caused by these types of HPV, up to a period of 4 years after vaccination.
- Why are these vaccines important?
They are potentially capable of reducing the number of deaths from cervical cancer worldwide by two thirds. Furthermore, these vaccines can obviate the need for medical care, biopsies and invasive measures associated with follow-up procedures after abnormal results for the Papanicolaou test.
- How safe are anti-HPV vaccines?
Before authorizing any vaccine, the FDA must verify that it is both effective and safe. These vaccines have been tested on thousands of people in the USA and many other countries. No serious secondary effects have been reported to date. The most common problem is a brief pain in the injected area and other symptoms normally associated with other approved vaccines.
- How long do they provide protection against the infection?
This remains to be determined. To date, however, they are known to provide protection against HPV 16 for up to 4 years. Research on vaccines currently undergoing trials shows that they provide protection against infection by HPV 16 and 18 for more than 4 years.
- Are booster shots necessary?
Trials are being carried out to determine the necessity of booster shots (complementary doses of a vaccine, usually weaker than the first dose, that are given to maintain immunity).
- Who should be vaccinated against HPV?
Vaccines are only effective if they are given prior to HPV infection; it is advisable to administer them before the individual becomes sexually active. The FDA approved this vaccine for females between the ages of 9 and 26 years.
- Should people already infected by HPV be vaccinated?
The preventive vaccines currently being researched do not treat infections, although in general they have been proved to be safe when administered to women already infected by HPV. At present, there is in general no examination available to check if a person has been exposed to HPV; it only shows whether a women has an HPV infection and identifies the HPV type. It provides no information about past infections. The decision whether or not to administer the vaccine on the basis of possible previous exposure to these types of HPV is currently being discussed by the Advisory Committee on Immunization Practices and by other advisory bodies.
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Monday | 10.00 - 15.00 h | 16.00 - 19.00 h |
Tuesday | 10.00 - 13.00 h | 16.00 - 20.30 h |
Wednesday | 10.00 - 15.00 h | 16.00 - 19.00 h |
Thursday | 10.00 - 13.00 h | 16.00 - 20.30 h |
Friday | 09.00 - 14.00 h | 15.00 - 19.00 h |