British Columbia launched routine immunization against human papillomavirus (HPV) in the school year 2008–2009. Two cohorts of girls were targeted—grades 6 and 9—in order to see benefits earlier, given the latency between HPV infection and cervical abnormalities, including cancer.
Mathematical modeling had demonstrated that beginning immunization of girls at 11 years was associated with the greatest reduction in future incidence of cervical cancer abnormalities. A BC-based economic analysis found that a female-only vaccination program of grade 6 and 9 girls was cost effective compared to no vaccination, at a cost of $24491 per quality adjusted life year gained. Similar findings have been seen in a variety of other economic analyses of HPV vaccine, which indicate that female-only vaccination is cost effective.
The grade 9 HPV vaccine program for girls in BC was designed to run for only 3 years, with the 2010–2011 school year the third and final year, following which time girls entering grade 9 would have an opportunity to be vaccinated if they haven’t been previously. The HPV vaccine would continue to be offered in school only at grade 6. Girls who miss the vaccine while passing through the targeted grade are eligible to be vaccinated through the publicly funded program on an appointment basis through their local health unit.
BC school-based immunization programs have been successful in reaching a high proportion of students, with uptake of hepatitis B, meningococcal C, and Td/Tdap in the order of 90%. This same high uptake has not been achieved for HPV. In the first year of the program, the rate of series completion for HPV vaccine in grade 6 and 9 girls was 62%. While this rate was only slightly lower than the rate of series commencement, indicating very little attrition, it is almost 30% lower than what should be achievable. The preliminary data on uptake in the second year of the program indicate little change.
Part of the explanation for the low uptake is related to the perceived novelty of this vaccine, accompanied by negative media coverage following its approval. A parental attitudinal survey conducted prior to its introduction indicated that compared with parents in other provinces, BC parents stated the lowest intention to vaccinate their daughters.
A subsequent survey of grade 6 parents conducted in the first year of the program in BC indicated that concerns about vaccine safety, preference to wait until their daughter is older, and not enough information to make an informed decision were the key reasons parents stated for not having their daughter immunized.
Studies of the key drivers of decision making about vaccine receipt for all vaccines have repeatedly shown that the advice from a trusted health care provider is highly influential. To ensure BC physicians feel well informed about the HPV vaccine and have the information they need to address questions from young women and their parents, a series of continuing medical education events is rolling out across BC and was advertised in the January/February issue of the BCMJ and on the immunizebc.ca web site.
These “ImmunizeBC Booster Events” in Kelowna, Prince George, and Dawson Creek in March, aim to boost your confidence in answering questions about the HPV vaccine. All practitioners who provide services to girls and their parents are encouraged to attend.
Over the past year the indications for the HPV vaccine have expanded internationally. The Food and Drug Administration in the United States approved the use of Gardasil for males ages 9 to 26 years old for prevention of genital warts. The Advisory Committee on Immunization Practices in the US has supported permissive use of the quadrivalent HPV vaccine, leaving decisions on whether to immunize males ages 9 to 26 years who request the vaccine up to their health care professionals.
In addition, the US FDA approved use of the HPV vaccine, Cervarix, the new bivalent HPV vaccine manufactured by GlaxoSmithKline Biologicals, for the prevention of cervical cancer and precancerous lesions caused by HPV types 16 and 18 in girls and women ages 10 to 25 years.
For more news, check our web sites periodically at www.bccdc.org and immunizebc.ca.
1. What is the role of the duration of human papillomavirus vaccine-related immunity? J Infect Dis 2008;197:1653-1661.
2. Marra F, Cloutier K, Oteng B, et al. Effectiveness and cost effectiveness of human papillomavirus vaccine: A systematic review. Pharmacoeconomics 2009;27:127-147.
3. Immunization coverage: School age children. Statistical reports available from the BC Centre for Disease Control. www.bccdc.ca/imm-vac/BCImmunizationCov/schoolagecoverage/default.htm (accessed 25 January 2010).
4. Ogilvie GS, Remple VP, Marra F, et al. Parental intention to have daughters receive the human papillomavirus vaccine. CMAJ 2007;177:1506-1512.
5. Ogilvie G, Anderson M, Marra F, et al. Factors associated with uptake of the HPV vaccine in a provincially funded, school based program in Canada: A population based assessment. 25th International Papillomavirus Conference, Malmo, Sweden, 8–14 May 2009.
Dr Naus is the director of the Immunization Program and associate director of Epidemiology Services at the BC Centre for Disease Control. She is also an assistant professor at the School of Population and Public Health at the University of British Columbia. Dr Ogilvie is the associate medical director of the Division of STI/HIV Prevention and Control at BCCDC and an assistant professor in the Division of Family Practice at UBC.