How do hpv vaccines work

HPV is the most common sexually transmitted disease in the United States and in the world. Twenty million Americans are currently infected with HPV and an additional 6 million Americans are infected every year.

Half of those newly infected with HPV are between 15 and 24 years of age. Although most HPV infections typically resolve on their own, some persist. Every year in the United States:. HPV is transmitted from one person to another by genital contact. Although this most often occurs during sexual intercourse, it can also occur during oral or anal sex or through genital-to-genital contact in the absence of sexual intercourse.

HPV infections are unique. First, most people never know they were infected. Unlike a cold in which symptoms develop a few days after exposure to the virus, HPV infections are typically not symptomatic. Second, HPV infections can last for long periods of time. The average length of infection is about eight months; however, for about 1 of every 10 women, the infection lasts longer than two years. It is in this group of women that there is an increased risk of developing cervical cancer.

Sometimes people can be infected with HPV and not know it. So HPV can be difficult to avoid. The best way to avoid genital infection with HPV is abstinence. You can also decrease your chance of getting HPV by having sex with only one other person who isn't infected with HPV.

While condoms may also decrease the chance of getting HPV, they do not always work to prevent the spread of the infection. Because other than abstinence, none of these measures can completely protect someone from becoming infected or prevent the spread of this infection, the development of a vaccine was an important tool for preventing future generations from experiencing the devastation caused by HPV.

At one time cervical cancer was the most common cause of cancer in the United States. One test changed that: the Papanicolaou Pap test. The Pap test is performed by scraping cells from the opening of the cervix and examining them under the microscope to see whether they have begun to show changes consistent with the early development of cancer called pre-cancerous changes. Typically, the length of time from infection with HPV to development of cervical cancer is about years.

For this reason, although most HPV infections occur in teenagers and young adults, cervical cancer is more common in women in their 40s and 50s. The Pap test is one of the most effective cancer screening tests available and has dramatically reduced the incidence of cervical cancer in the United States. But the test isn't perfect and not all women get tested as often as they should.

On the flip side, even if you have been vaccinated against HPV, you are still recommended to get the Pap test. HPV infections cannot be treated; however, the symptoms of HPV can be treated, at least to some extent.

For example, genital warts can be treated with medications or surgically removed; however, they may return, and the patient may still be infected with HPV and could, therefore, still transmit the infection.

The HPV vaccine is made using a protein that resides on the surface of the virus. The protein is grown in the lab in yeast cells. The vaccine is composed of the surface protein from nine different types of HPV. The vaccine is given as two shots separated by 6 to 12 months if started before 15 years of age. For those 15 years and older, and teens of any age with a compromised immune system, three doses are recommended.

The second shot should be given one to two months after the first, and the third shot, six months after the first. Recently, the HPV vaccine was licensed for use in people up to 45 years of age.

Learn more about why adolescents and teens are recommended to get HPV vaccine by watching this short video, part of the series Talking About Vaccines with Dr.

Paul Offit. The HPV vaccine was originally studied in about 30, girls and young women between 9 and 26 years of age. Studies determined that the vaccine prevented 9 of 10 HPV infections and was completely effective at preventing persistent infections and Pap smear changes that predict cervical cancer. In Australia, where a school-based immunization program was implemented, they have seen dramatic reductions in pre-cancerous cervical changes in young women as well as genital warts in both young men and young women.

Because the HPV vaccine is made using only the surface protein from the virus, it can't cause HPV and, therefore, can't cause cervical cancer. The vaccine may cause redness and tenderness at the site of injection.

The vaccine may also cause a low-grade fever in a small number of recipients. More than million doses of HPV vaccine have been given to people in the United States, and safety networks have continued to monitor reactions to the HPV vaccine since its licensure. While fainting episodes following HPV vaccination have been reported, the rates have not been higher than those following receipt of other vaccines for teens. Because of the possibility of fainting, teens are recommended to remain at the office for about 15 minutes after getting immunized.

HPV tests for men are not available, and most HPV infections clear on their own without causing problems. However, health problems caused by HPV, which can include genital warts, anal cancer, penile cancer or cancers of the head and neck, can be checked by visiting your doctor. Both tests detect early health problems that can lead to cervical cancer, but neither checks for warning signs of other cancers, fertility or other STDs.

Although both tests have a common goal, they do have their differences:. If both tests are normal, it is highly unlikely that serious cervical cell changes will develop in the next three years; however, regular wellness visits should not be skipped. If either test is abnormal, more testing will be completed. Abnormal results do not mean that you have cervical cancer, but that cells in your cervix could eventually become cancerous. However, finding the abnormal cells early allows for more successful treatment.

Because the vaccine doesn't prevent all types of HPV that cause cancer, women still need to get routine Pap tests. The HPV vaccine doesn't prevent other sexually transmitted diseases such as syphilis, gonorrhea, chlamydia and herpes virus, and the HPV vaccine doesn't prevent all of the dangerous types of HPV; it prevents most of them.

Vaccinated individuals should still practice safe sexual behaviors monogamy or limiting the number of sexual partners, and condom use.

Unfortunately, therapeutic trials of HPV vaccine have shown that the vaccine doesn't cause a regression in Pap smear changes that precede cervical cancer. The HPV vaccine protects against certain cancers and genital warts, and it is safe. The only known side effects are mild, such as pain, redness or swelling at the injection site or low-grade fever. Therefore, the benefits of the HPV vaccine outweigh its risks. Adolescents, beginning at age 9, and teens; adults up to 45 years old who want to protect themselves.

Human papillomavirus vaccines in Vaccines, 7th Edition. Human Vaccines and Immunotherapy ; epub ahead of print. The HPV vaccine adjuvant was composed of monophosphoryl-lipid A plus aluminum salts. The incidence of new-onset autoimmune diseases was similar in both vaccine groups. Similarly, those receiving HPV vaccine during pregnancy did not have an increased risk for spontaneous abortion or congenital anomalies. Quadrivalent human papillomavirus vaccination in boys and risk of autoimmune diseases, neurological diseases and venous thromboembolism.

International Journal of Epidemiology ;47 2 The authors investigated the association of quadrivalent HPV qHPV vaccination and the risk of 39 autoimmune diseases, 12 neurological diseases, or venous thromboembolism over a year period in more than 7, Danish boys who received at least one dose of qHPV vaccination at the age of 10 to 17 years by comparing them to more than , boys who did not receive the vaccine.

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Legislative Resources. Recent Public Laws. Search Search. Cancer-Causing Substances. Chronic Inflammation. Common Cancer Myths and Misconceptions. Infectious Agents. Who should get HPV vaccination? How many doses of HPV vaccine are needed? How effective are HPV vaccines? How do HPV vaccines work? Why is HPV vaccination important? Are HPV vaccines safe? Do women who have been vaccinated against HPV still need to be screened for cervical cancer? How much does HPV vaccination cost, and will insurance pay for it?

What research is being done on strategies to prevent HPV infection? What are HPV vaccines? HPV vaccination is routinely recommended at age 11 or 12 years; vaccination can be started at age 9 years. HPV vaccination is recommended for all persons through age 26 years who were not adequately vaccinated earlier.

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Something went wrong on our side, please try again. Centers for Disease Control and Prevention. Accessed May 20, HPV vaccine schedule and dosing. Human papillomavirus vaccination. Human papillomarivirus 9-valent vaccine, recombinant. IBM Micromedex.