In 2009, the FDA licensed bivalent HPV vaccine Cervarix (GlaxoSmithKline) for use in females aged 10 through 25 years. Cervarix is indicated to prevent cervical cancer, cervical intraepithelial neoplasia (CIN) grade 1, grade 2 or worse and adenocarcinoma in situ (AIS), caused by HPV types 16 and 18.
The bivalent HPV vaccine prevents the two HPV types, 16 and 18, which cause 70% of cervical cancers. The quadrivalent HPV vaccine prevents four HPV types: HPV 16 and 18, as well as HPV 6 and 11, which together cause 90% of genital warts. Quadrivalent vaccine has also been shown to protect against cancers of the anus, vagina and vulva. Only the quadrivalent vaccine is licensed in use for males. While both vaccines are effective in preventing HPV-related diseases, a study published in the BMJ demonstrated that the bivalent vaccine may be more effective in preventing death due to cervical cancer.
Both HPV vaccines have no therapeutic effect on HPV-related disease, so they will not treat existing diseases or conditions caused by HPV. The vaccines are made from non-infectious HPV virus-like particles (VLPs) and do not contain thimerosal or mercury as a preservative.
Ideally, patients should be vaccinated before onset of sexual activity, when they may be exposed to HPV. Patients who have been infected with one or more HPV types still get protection from the vaccine types they have not acquired.
Either HPV vaccine is routinely recommended for 11- or 12-year-old girls. Quadrivalent HPV vaccine is routinely recommended for 11- or 12-year-old boys. The vaccine series can be started beginning at age 9 years. Vaccination is also recommended for 13- through 26-year-old females and 13- through 21-year-old males who have not completed the vaccine series. Quadrivalent HPV vaccine may be given to 22- through 26-year-old males. Vaccination is routinely recommended for both men who have sex with men (MSM) and immunocompromised persons aged 22 through 26 years.
The CDC recommends that healthcare providers recommend HPV vaccination the same way they recommend other adolescent vaccines. Parents may be hesitant to vaccinate their children because they believe that vaccinating may be perceived by the child as permission to have sex. Clinicians should be ready to discuss the importance of vaccination with parents and how it may help protect the child from HPV-related cancers in the future. Data from the 2011 National Immunization Survey showed that among females and males who initiated the HPV series, 70.7% and 28.1% received 3 doses, respectively. These numbers indicate that girls still seem to be the primary focus for vaccination.
While neither of these vaccines has been studied in the prevention of oropharyngeal cancers, it is still important for patients to be vaccinated to prevent other HPV-related diseases. Healthcare providers should also counsel patients on appropriate barrier methods that may be used during oral sex. Michael Douglas may have brought HPV and oropharyngeal cancer into the news, but it is the clinician’s responsibility to answer the relevant questions surrounding the disease.
For more information visit www.cdc.gov/std/hpv/stdfact-hpv-vaccine-hcp.htm