Human Papillomavirus / HPV and HPV vaccine
What is Human Papillomavirus / HPV
Human papillomavirus (HPV) is the most common sexually transmitted virus in the U.S. According to the Centers for Disease Control and Prevention, (CDC), an estimated 20 million adults currently have HPV and 6.2 million will contract it each year. The virus can cause symptoms ranging from genital warts to an illness that precedes and eventually develops into cancer, particularly cancer of the cervix in females.
What is HPV?
HPV is a virus of which about 120 identified types or strains have been identified. Of those, approximately 13 – 18 types are categorized as high risk, which means a persistent infection has an increased likelihood of developing into cancer. The other, lower risk forms of the HPV virus cause either minor symptoms, such as genital warts, or are asymptomatic. The most high-risk HPV types are identified by the numbers 16 and 18, which together are responsible of nearly 70% of cervical cancer cases. The HPV viruses that can lead to cancer alter normal cells that become damaged and may lead to an over-proliferation, which would develop into a tumor. In addition to cervical cancer, HPV can also cause cancers of the vulva, vagina, penis and anus. A more rare condition that HPV may cause is recurrent respiratory papillomatosis (RRP), which involves the occurrence of warts in the throat and respiratory system. In approximately 90% of people who contract HPV, the body’s immune system naturally removes any detectable level and associated risks within two years.
Where does HPV come from?
HPV is now an important epidemiological research area because it is a precursor to cervical cancer. Furthermore, HPV is not only the most common sexually transmitted disease, it also has high-risk consequences. Scientists first linked sexual behavior with cervical cancer incidence in the 1960s, but the relationship had been gaining scrutiny among medical experts prior to the discovery for more than a century. Finally, in the early 1980s, HPV DNA was identified in cervical cancer cells by Harald zur Hausen, and medical studies published in the 1990s were further explicating the link between HPV and cervical cancer. Later in 2006, medical companies developed the first HPV vaccine to prevent infection with four types thought to be the most high-risk and common.
How is HPV transmitted?
The reason most medical experts believe that HPV is so common is that it is not transmitted through bodily fluids, unlike most sexually transmitted diseases. Instead, an HPV infection can be acquired through direct genital skin contact. HPV is also most easily transmitted to the cervix through male-to-female intercourse. Some estimates show that as many as 64% of sexually active adolescent girls are infected, and 80% of sexually active women will become infected with HPV at some point during her lifetime. More than half of sexually active men will contract HPV at some point in their lives. HPV in women is most commonly caused by receptive heterosexual intercourse. Other transmission routes include oral-genital and anal intercourse, and may affect both heterosexual, homosexual and bisexual men and women. The HPV virus may also remain active on inanimate surfaces; however, it is thought to not survive for a lengthy period of time. Risk factors for contracting HPV include a high number of lifetime sexual partners, a younger age when beginning to engage in sexual relations, not using a condom when having sex, and having a sexual partner who has had multiple sexual partners. It is still unclear when and for how long HPV is contagious, but most researchers believe that it is most contagious when warts are present.
What are HPV symptoms?
The average length of time an HPV infection will remain in the body is 4 – 20 months. Among the mildest symptoms of HPV are genital warts, which appears as a small bump or group of bumps in the genital region. The warts can vary in size, be flat or raised or cauliflower shaped. Genital warts can be diagnosed visually during a medical exam when the virus is active and warts appear on the skin, usually within weeks or months after contracting the virus from an infected partner. HPV warts do not turn into cancer. HPV may also be diagnosed in a female pelvic exam pap smear if a sampling of cells successfully exposes its presence. Symptoms like irregular bleeding or discharge do not appear until the disease is advanced, and diagnosing HPV-related cervical cancer requires a laboratory test during a routine pelvic exam. If a woman does develop cervical cancer, nearly always an HPV infection would have caused it. HPV in men rarely presents itself, with only 1% of sexually active men developing genital warts from the virus. Symptoms of anal cancer can include itching, bleeding, and pain, while symptoms of penile cancer may be changing color, skin thickening or a growing sore. Oral cancers may be accompanied by a sore throat or ear pain, constant coughing, pain while swallowing or breathing, and a lump in the neck.
What is the HPV vaccine?
HPV vaccination is thought to be a highly effective immunization method that involves administration of a shot prior to sexual intercourse that could expose an individual to HPV. By July of 2012, nearly 46 million doses of HPV vaccine had been administered in the United States. Two types are currently available to prevent HPV, including Cervarix and Gardasil. Both vaccines are recombinant vaccines that are intramuscular injections, containing specific protein from each of the four virus types of HPV; therefore, the HPV Vaccine cannot cause and HPV infection. In addition to targeting cervical cancer HPV strain prevention, Gardasil may also prevent genital warts and anus, vagina and vulva cancers. Only Gardasil is available for men. It is thought to start immunization before the onset of sexual activity in order to allow time for the vaccine to become effective. The vaccine is frequently recommended for adolescent boys and girls before they become sexually active, and adult men and women before age 26 when sexual activity tends to be the highest. Furthermore, the HPV vaccine is recommended for homosexual/bisexual men, and men and women with compromised immune systems through the age of 26.
What are the HPV vaccine side effects?
Studies have demonstrated no serious side effects from both HPV vaccines. Mild side effects may include a pain, redness, swelling, mild fever, nausea and a headache. The CDC and Food and Drug Administration continue to monitor its safety, and no serious adverse side effects have been reported.
Who should not get the HPV vaccine?
Anyone with a severe (life-threatening) allergy to any component of the vaccine or a previous dose of the HPV vaccine should not receive the vaccine. To exercise caution for the safety of the fetus, pregnant women should not be immunized against HPV until following the pregnancy. People who are moderately or severely ill during the time of the scheduled vaccine should wait.