Updated: January 4, 2012
Human papillomaviruses (HPVs) are a group of more than 120 different viruses. Some are acquired by intimate sexual contact.
Approximately 40 HPV types are primarily sexually transmitted from person to person (for example, genital-genital contact, oral-genital contact and sexual intercourse), infecting the oral, anal or genital areas of both men and women. Genital HPV infections are very common: acquisition shortly after starting to have sex occurs commonly. One quarter of females 15-19 years of age and 45% of those who are 20-24 years of age have evidence of genital HPV infection. By 50 years of age, 70-80% of women and a similar percentage of men will have acquired genital HPV infection.
Most HPV infections cause no symptoms and are cleared by the immune system within a few weeks or months. Thus, the vast majority of people recover from HPV infection uneventfully. However, some people develop persistent HPV infection, some of which can lead to genital warts and others can cause cancers:
Product: Gardasil (HPV4)
Year Licensed: 2006
Product: Cervarix (HPV2)
Year Licensed: 2009
A Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) recombinant vaccine (HPV4) was licensed for use in females by the Food and Drug Administration in 2006 and a bivalent vaccine (Types 16 & 18) (HPV2) in 2009. In 2009, HPV4 was also licensed for the prevention of warts in males and, in 2010, for the prevention of anal cancers in both males and females. Both vaccines are effective at preventing HPV infections of the specific types contained in the vaccines and, therefore, prevent precancers and cancers due to HPV 16 and 18. HPV4 has also been shown to prevent genital warts due to HPV 6 & 11 in both males and females.
Who should receive the HPV vaccine?
Women who are breastfeeding can receive the HPV vaccine. Also, immunocompromised persons (from disease or medication) can receive the vaccine; however, the immune response to vaccination and vaccine effectiveness might be less than in persons who are not immunocompromised.
Who should not receive the HPV vaccine?
Each dose of HPV4 vaccine is 0.5 mL, administered intramuscularly. It should be administered in a three dose schedule. The second dose should be administered 1-2 months after the first dose and the third dose should be administered 6 months (at least 24 weeks) after the first dose.
HPV4 vaccine can be administered at the same visit when other age appropriate vaccines are provided, such as Tdap and MCV4.
The efficacy of both HPV vaccines for preventing persistent infection, cervical precancer, and cervical cancer have been studied extensively in women 16-26 years of age. In women who previously had not been exposed to the HPV types in the vaccine, the vaccines were highly efficacious as well effective in preventing vulvar and vaginal precancers. HPV4 has also been shown to be highly effective at prevention of genital warts and other types of precancerous lesions in both men and women caused by the HPV types in the vaccines.
HPV vaccines do not prevent chronic HPV infection or the development of disease caused by HPV in persons already infected with one of the HPV types in the vaccine.
How long the vaccines will protect those who have been immunized is not yet known although waning serologic immunity does not seem to indicate a loss of immunity.
The HPV vaccines have been tested in large numbers of vaccinees in many countries around the world, including the United States. These studies found that the HPV vaccines were safe and caused no serious side effects. Vaccine recipients experienced pain, swelling and redness at the injection sites, however. Vaccine Safety Datalink studies from more than 600,000 HPV4 doses administered showed no increased risk for Guillan-Barré syndrome, stroke, venous thomboembolism, appendicitis,seizure, fainting, and allergic reactions, including anaphylaxis.
However, immunizations in general in preteens and teenage patients, especially females, has been associated with fainting, suggesting that patients should remain seated for a few minutes after vaccine administration.
The HPV vaccine does not contain thimerosal.
Because these HPV4 will only prevent infection with the two types of HPV that cause most cases of HPV-associated cancers and the two types that cause most cases of genital warts, the vaccine will not eliminate HPV-associated cancers nor eliminate genital warts. As a consequence, routine Pap screening and treatment programs for cervical cancer will remain important preventive medical interventions.
These vaccines are preventive and have no effect on pre-existing infection with these HPV types. Because HPVs are spread by intimate contact, some experts consider that universal immunization of children at 11-12 years of age (both boys and girls) may provide a greatly reduced disease burden caused by HPV 16 and 18 as a result of community immunity.