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PRIORITY PRESS - 8th Canadian Immunization Conference

Toronto, Ontario / November 30-December 3, 2008

Achieving optimal uptake of the human papillomavirus (HPV) vaccine hinges on education, which starts with physicians themselves being knowledgeable about HPV-related diseases and their prevention with the quadrivalent vaccine.

In a targeted literature review of the acceptability of the HPV vaccine among healthcare professionals, parents and young adults, investigators reported here that healthcare professionals’ knowledge about HPV and the HPV vaccine was varied but tended to be low (Delisle et al., Abstract 61517). For example, in a 2007 study by Esposito et al., investigators concluded that the level of knowledge among physicians about HPV and the HPV vaccine was poor, with most physicians giving wrong answers to questions about HPV-related disease.

Only about two-thirds of healthcare professionals surveyed in a separate study were aware that HPV causes the majority of cervical cancer, as Delisle et al. pointed out. More importantly, not being confident about the efficacy of the vaccine was one of the main reasons healthcare professionals indicated they were reluctant to recommend the vaccine, the group also noted. Also in 2007, Kahn et al. similarly found that concerns about the safety of the vaccine were among the primary factors driving physicians’ decisions not to recommend the vaccine. Thus, being knowledgeable about HPV and the HPV vaccine is the first step towards guaranteeing the vaccine reaches its target population, investigators concluded.

Evidence supporting the safety and efficacy of the quadrivalent vaccine is far from lacking. In the landmark FUTURE I trial involving 5455 HPV vaccine-type-negative females between the ages of 16 and 24 years, the quadrivalent vaccine proved to be 100% effective in preventing vaginal, vulvar, perineal and perianal intraepithelial lesions or warts caused by HPV types 6, 11, 16 and 18, according to the per-protocol cohort analysis. It was also 100% effective in preventing cervical intraepithelial neoplasia (CIN) grades 1 to 3 as well as adenocarcinoma in situ from HPV vaccine types in the per-protocol analysis.

In FUTURE II, investigators again found that the quadrivalent vaccine prevented 98% of HPV 16- and 18-related high-grade cervical lesions in the per protocol group. At 60 months, published data from a subset of the cohort from protocol 007 indicated vaccine efficacy against vaccine-type-related external genital lesions or CIN remained at 100%, a reflection of the robust immune-memory response that has been demonstrated with the quadrivalent vaccine.

Even in older, sexually active women between the ages of 24 and 45 years, researchers recently reported that the same quadrivalent vaccine was 92.4% effective in preventing HPV 6-, 11-, 16- and 18-related CIN and external genital lesions. It demonstrated 100% efficacy in preventing HPV 6- and 11-related external genital lesions and CIN in the same cohort.

These interim data demonstrate that the quadrivalent HPV vaccine is highly effective in preventing HPV 6-, 11- and 16/18-related CIN or external genital lesions in women aged 24 to 45 years, researchers concluded.

Public Confidence in Vaccine Safety is Key

During his presentation here on how to talk to parents and teens about HPV, safety issues are likewise paramount to address, noted Dr. Simon Dobson, Canadian Association for Immunization Research and Evaluation, Vancouver, British Columbia. To date, some 30 million doses of the HPV quadrivalent vaccine have been administered worldwide and still no safety signals have emerged from surveillance studies. Vaccine recipients are more likely to report local adverse effects so parents and their daughters should be told that they may experience some redness and swelling following vaccination.

However, parents also need to appreciate that the adverse events repeatedly reported by the media are based upon a passive adverse-event surveillance system in the US, where anybody can report any adverse event that may follow vaccination but which in no way implies the adverse event was caused by the vaccine, Dr. Dobson stressed. Parents also need to be impressed by the healthcare provider’s conviction that the vaccine is both safe and efficacious. “First impression is key,” he told delegates, “and if you as an immunization provider give a confident and optimistic impression about this vaccine and how important it is for parents and their daughters, this is key to what happens next.” However, the HPV story is complex, he cautioned, and physicians need to “layer” information about the vaccine a bit at a time, directing parents to reliable Web sites and other sources of information so they can learn more about it on their own if they remain doubtful, and bring them back for further counselling.

“Rather than fire statistics at them,” Dr. Dobson continued, “asking questions such as [whether they know] anybody who has had an abnormal PAP smear and who has had to do go through all of the subsequent procedures is also very helpful.” Framing the message from a daughter’s point of view makes that message much more powerful as well, he added. For example, physicians might ask parents how they think their daughter might feel if years later, she were to develop cervical cancer because they made a decision not have her vaccinated. “Faced with a difficult decision, the easiest thing to do is nothing,” Dr. Dobson remarked. In anticipation of “cognitive shortcuts” we all make when confronted with complicated information, Dr. Dobson felt it was important for physicians to give accurate risk data such as, “This is an opportunity to prevent 70% of cervical cancer against which the vaccine is almost 100% protective.”

Parents also need to understand that girls who are not vaccinated against HPV remain at risk for HPV infection because boys will continue to be a transvecting source of the virus, until such time as they are vaccinated against HPV as well. Healthcare professionals should also not assume that the school-based HPV vaccination programs will cover all eligible girls. Successful as many of these programs have been, it is important for physicians to appreciate that school-based programs target selected age cohorts only and girls who are outside of this targeted age cohort remain at risk for HPV infection. “When things get tough, I also tell a lot of personal anecdotes,” Dr. Dobson revealed. “But the key to the success of HPV vaccination program is public confidence in vaccine safety.”

The Role of Public Health Authorities

A number of presentations here by public health authorities underlined the fact that education of the public significantly increases the success of HPV vaccination. In one such example, regional health authorities in Newfoundland and Labrador made a concentrated effort to educate public health and communicable disease nurses so that they would be well prepared to address any concerns about the efficacy and safety of the vaccine when confronted with parents and adolescents. Following these efforts, at least 85% of eligible vaccine recipients have received the vaccine in this region.

The same effort was made in Toronto, where parents and teachers of grade 8 students were educated in several languages through a variety of resources. Out of 432 schools targeted with the educational program, 64% of the students had received the first dose of the HPV vaccine by September 2008, 62% had received the second dose and 56% had received the third. Eligibility for grade 8 girls to receive the vaccine in grade 9 has now been extended in the province, with expectations to reach the provincial goal of 85% vaccination coverage in the near future.