Larry Glazerman, MD
Dr. Harper responds:
Data are plentiful
I am happy to provide the data Dr. Glazerman requested. In regard to the need for a minimum of 15 years of protection for a vaccine to reduce the rate of cervical cancer, see Barnabas and colleagues and Berkhof and coworkers.1,2
Data on the shorter-lived titers induced by Gardasil for HPV 6, 11, and 18 can be found in Olsson and colleagues and Rowhani-Rahbar and associates.6,7 And data on Cervarix’s protection against five cancer-causing types of HPV are available in a report from the PATRICIA Study Group.8
Which vaccine would the panelists choose?
I enjoyed reading the differing opinions of the expert panelists who participated in the HPV vaccine roundtable discussion—but I found the discussion slightly confusing, too. I wish someone had asked the panelists whether they’d be willing to vaccinate themselves, and, if so, which vaccine they would choose.
I know the option of choosing both vaccines is not cost-effective, but there are patients who can afford to do so and who would be willing to do so. What are the benefits and risks of this approach?
Dennis A. Fito, MD
They’re asking about getting both vaccines
Patients have asked me whether there are any data on the benefits and risks of taking both Gardasil and Cervarix. How would the panel respond?
James W. Browne, MD
How might the HPV vaccines affect other cancers?
Would Dr. Lonky or any of the panelists care to comment on the prevalence of HPV in oral and esophageal cancers and how the quadrivalent and bivalent vaccines (Gardasil and Cervarix) might affect it?
What about the efficacy of one dose of Cervarix followed by the full series of Gardasil? Are there any studies of the practice of administering one or two doses of each vaccine?
Helen Sandland, MD
Dr. Lonky responds:
Context is everything
It is not realistic to ask a male panelist who is in his 50s which vaccine he would choose for himself. Even so, I would not “endorse” either vaccine. In fact, I think the data on cancer prevention and overall safety are too controversial for me to advocate for either vaccine at this time.
Were I a young woman (and assuming that the vaccines have similar side-effect profiles), my choice would likely be based upon which vaccine is more affordable, a lower cost making it easier to complete the series. Were either vaccine to demonstrate clear-cut superiority in terms of efficacy or a streamlined vaccination schedule, it would have the advantage.
If I were the director of a health plan or medical group and thus had data on the total cost of managing both premalignant and benign HPV-related disease, that information would drive my recommendations to the patient. We know that both vaccines should prevent encounters related to colposcopic evaluation. The costs associated with encounters for benign genital warts, if reduced by vaccinating early against HPV types 6 and 11, would provide additional savings to the patient and the health-care system as a whole. As a result, I would lean toward advocating for Gardasil (which has had a commercial head start). If clear-cut evidence later revealed that Cervarix is similarly effective in preventing benign HPV disease, or offers a superior vaccination regimen, the scale would tip back toward Cervarix.
Ultimately, however, it is up to the patient to decide, after being informed about cost, risk of malignancy, morbidity of HPV-related disease, and so on. If she does not agree with her insurer’s choice, she is free to go elsewhere, perhaps even to have the vaccine covered or subsidized by the government.
Dr. Felix responds:
The prevalence of HPV in oropharyngeal cancers ranges from 20% to 40%, depending on the series. Most recent series estimate prevalence closer to 40%. The most prevalent HPV types are 16 and 18—these two strains account for almost 80% of oropharyngeal carcinomas that are caused by HPV.
Although there have been no clinical trials assessing the efficacy of either vaccine in preventing oropharyngeal HPV, either should work as well as it does in the cervix. Both vaccines provide coverage against HPV 16 and 18, so they would be equally effective.
Dr. Harper responds:
All of the panelists are older than 26 years, and three of them are men, which means that none of them have the option of choosing vaccination for themselves.