Urgent need for uptake data on 3 doses of HPV vaccine
Brabin et al need to be congratulated on their feasibility study of HPV vaccine administration in Manchester (BMJ, on line first, 24th April 2008) and also the BMJ for publishing the study on line within a few weeks of its acceptance. However, I would like to share some of my concerns with this study and the way it has been covered in the media. It is important to note that reference 2 cited in the paper, a systematic review (1), only included women aged 15 to 25 years and the authors caution against its external validity to women outside of this age group. They have also explicitly stated that “We did not find evidence that prophylactic vaccination against HPV types 16 and 18 reduces cervical cancer incidence or mortality”. However, reference 3 in the BMJ paper of which Brabin L is also the first author when presenting information to the participants of the study (2) stated, “Vaccination against HPV will prevent cervical cancer”.(Box 1, p 3088). There are also problems with response rates in both surveys cited as ref 3 and 4 with response rates of 22.7% (2) and 56.7% (3), respectively. The non response bias in lifestyle survey studies are well known (4).
The key point of concern with this study is the way the study findings and conclusions were covered in the media. The first author has been quoted as saying “We were very encouraged, and believe that a coverage of 80% is very achievable”. This can be misleading as the study is only reporting the first two doses of the vaccine and not the full course which should include the third dose. As the authors have pointed out themselves “success of the vaccination programme depends on high coverage of third dose”. As stated in the Canadian consensus guideline (5) it is important to have all three doses of the vaccine to derive benefit. Hence one would have expected both the authors and the BMJ to have waited and published the uptake and acceptance at the completion of the proposed vaccination schedule. As the study commenced a year ago (February 2007), it is possible that this data might already be available. The sceptics among your readers might speculate about the possible uptake of the three doses at the end of 6 months and the potential reasons for it being not made available in the scientific literature. For both national planners and local implementers this will be key outcome which I hope will be made available as soon as possible.
References 1 Rambout L, Hopkins L, Hutton B, Fergusson D. Prophylactic vaccination against human papillomavirus infection and disease in women: a systematic review of randomized controlled trials. CMAJ. 2007 Aug 28;177(5):469-79.
2 Brabin L, Roberts SA, Farzaneh F, Kitchener HC. Future acceptance of adolescent human papillomavirus vaccination: a survey of parental attitudes. Vaccine. 2006 Apr 12;24(16):3087-94.
3 Marlow LA, Waller J, Wardle J. Parental attitudes to pre-pubertal HPV vaccination. Vaccine. 2007 Mar 1;25(11):1945-52.
4 Hill A, Roberts J, Ewings P, Gunnell D. Non-response bias in a lifestyle survey. J Public Health Med. 1997 Jun;19(2):203-7.
5 Canadian consensus guidelines on Human Papilloma virus. http://caonline.amcancersoc.org/cgi/content/full/57/1/7 Accessed on 25th April 2008.
Competing interests: Conflict of interest: The author works in the area of clinical prioritisation and firmly believes in the deployment of health care resources based on the information on clinical & cost effectiveness of health care interventions.
Competing interests: No competing interests