2 HPV vaccines, 7 questions that you need answered
Neal M. Lonky, MD, MPH, and an expert panel
The FDA recently approved the quadrivalent formulation of the human papillomavirus (HPV) vaccine (Merck’s Gardasil) for prevention of anal cancer and associated precancerous lesions caused by HPV types 6, 11, 16, and 18 in people 9 to 26 years old.
The quadrivalent HPV vaccine is already approved for the same age population for the prevention of cervical, vulvar, and vaginal cancer and the associated precancerous lesions caused by HPV types 6, 11, 16, and 18 in females. In addition, it is approved for the prevention of genital warts caused by types 6 and 11 in both males and females.
The indication for anal cancer prevention does not extend to the other FDA-approved HPV vaccine (GlaxoSmithKline’s bivalent [types 16 and 18] formulation, Cervarix).
“Treatment for anal cancer is challenging; the use of Gardasil as a method of prevention is important, as it may result in fewer diagnoses and the subsequent surgery, radiation or chemotherapy that individuals need to endure,” said Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research.
Anal cancer is uncommon in the general population, but incidence is increasing. HPV is associated with approximately 90% of anal cancer cases. The American Cancer Society estimates that approximately 5,300 people are given a diagnosis of anal cancer each year in the United States—more often women than men.
Gardasil will not prevent development of anal precancerous lesions associated with HPV infection that is already present at the time of vaccination. Its full potential for benefit—across all FDA-approved indications—is obtained by people who are vaccinated before they are exposed to HPV strains contained in the vaccine.
People who undergo regular screening for anal cancer on the recommendation of their health care provider should not discontinue screening after they receive the quadrivalent HPV vaccine.