This news release has several strengths. It carefully describes an important study comparing two forms of human papillomavirus (HPV) vaccine and provides the reader with information on the potential impact of HPV infections. However, it doesn’t deliver fully on several of our other criteria including costs, quantification of benefits, and harms.
We also think that it is important from a public health perspective to discuss use of the vaccine in the context of screening programs for cervical cancer (e.g. Pap tests). While the release does mention screening, it does so only in passing. The vaccine can greatly reduce the risk that immunized girls will develop cervical cancer in the future, but it cannot totally eliminate that risk, even when all three doses are administered. In addition, the rates of complete vaccination among eligible girls is not ideal, and a few words about the importance of completion would have added to the release.
HPV infection occurs in just about every sexually active adult. In the vast majority of cases, its presence produces no lasting effects. Depending of the strain of virus and other factors, however, the virus can cause a number of genital conditions including genital cancers. A vaccine that lowers risk when administered prior to sexual activity in girls is a significant step toward reducing the burden of the disease. This release highlights the results of a study that compared two forms of the vaccine that target different HPV subtypes.
The release is from the UK and likely written for a UK audience, which would expect the cost of the vaccine to be covered under the NHS vaccination program. (The release mentions that the current vaccine is covered by NHS.) However, the release does not provide any detail on what the vaccine costs per person or what the vaccination program costs NHS — which is something we think even readers in the UK would be interested in and deserve to know. For our U.S. readers, we’d note that the vaccine requires three doses and therefore three different office visits. The costs of the visits and the vaccines ($130-140 per dose) bring the total immunization cost to approximately $500. Insurance usually covers a portion of the costs, but patients may have copayments.
The release headline says the new version of the vaccine is “better” than the existing version, and the study backs this up. As the release notes, “ Gardasil 9 was 97 per cent effective at preventing high-grade cervical, vulvar and vaginal disease caused by HPV 31, 33, 45, 52 and 58, and was equally effective as the current Gardasil vaccine in preventing diseases caused by HPV 6, 11, 16 and 18.”
But while “97 percent effective” sounds very impressive, what exactly does that mean? “97 percent effective” compared with what? The study published in the NEJM has the statistics that can put this into perspective. The paper notes the exact rate of disease that was observed in both the old and new vaccine groups: “The rate of high-grade cervical, vulvar, or vaginal disease related to [various HPV subtypes] … was 0.1 per 1000 person-years in the 9vHPV [new vaccine] group and 1.6 per 1000 person-years in the qHPV [existing vaccine] group.” For a more reader-friendly description, the release could have said the rates were 0.1 vs. 1.6 cases per thousand people in the study annually.
In addition, the accompanying editorial in the NEJM rightly points to the less than spectacular successes to date in actually immunizing young and adolescent girls with three doses over 6 months. “At 57%, coverage for the first dose of HPV vaccination among girls 13 to 17 years of age lags behind coverage for other vaccines recommended for children 11 to 12 years of age by approximately 20 to 25 percentage points.” Greater emphasis on the need to follow through with all three doses would have been welcome.
The only mention of potential harms from the new vaccine come from a study author who says, “This is a significant achievement. The new vaccine, Gardasil 9, is not only safe but will offer greatly improved protection against cervical and other cancers.” Indeed, the vaccine appears to be safe, but we think that a complete disclosure of the adverse events observed in the study would have been helpful. The conclusion in the research notes, “Adverse events related to injection site were more common in the 9vHPV group than in the qHPV group.” So yes, the vaccine is safe, but appears to have more issues at the injection site than the existing vaccines. This is important because not all girls carry through with all three vaccinations; the lack of follow-through may be related to pain on injection.
The release notes that the vaccine has been approved by the US FDA on the basis of the study being reported on. It also provides some information about the study itself, noting that it was a “clinical trial [comparing] the safety and efficacy of the new vaccine, Gardasil 9, with the current vaccine, Gardasil, in more than 14,200 women aged between 16 and 26 years old. ” Ideally we should have been told it was a randomized double blind study and the study duration was 6 months. Some detail about the demographics of the women in the study would also have been helpful. However, we think the release provides enough information for readers to be assured of the study’s overall quality.
The release doesn’t exaggerate the burden of HPV infection or cervical cancer. In fact, we think the release could have done more to create urgency around the need to vaccinate.
The release points out that the study was funded by the manufacturer of the vaccine and that Dr. Cuzick was a coauthor of the study.
The release does point out that there are two older vaccines that are available. It notes that the quadrivalent vaccine protects against 4 strains of HPV, offering about 70 percent protection against cervical cancer, whereas the 9-valent vaccine protects against 9 strains and can prevent up to 90 percent of all cervical cancers. The release also mentions in passing that the vaccine can be discussed as part of a screening program in women ages 25 to 45. We feel that the release could have emphasized this more.
The release makes it clear that the new vaccine is available in the US but not yet in the UK.
The release makes it clear that the study is the first of its kind comparing two types of HPV vaccine.
Quotes from Dr. Cuzik are enthusiastic but could not be described as unjustified. He says, “This is a significant achievement. The new vaccine, Gardasil 9, is not only safe but will offer greatly improved protection against cervical and other cancers. Eventually this will mean less screening is needed, as women will have greater protection from the outset.” We’d add that while his statement may be accurate, the promise of the vaccine will only be achieved with higher vaccination rates