Assessing the effectiveness of human papillomavirus (HPV) vaccination to prevent cervical cancer: perspectives from Germany

J Epidemiol Community Health

February 2010 Vol 64 No 2

For approximately 2 years now, cervical cancer has been “converted” from an oncological disease to an infectious disease, which is said to be preventable by and large by two vaccines licensed in many countries. However, human papillomavirus (HPV) vaccines differ from existing others, as the former target  a condition which only in a minute fraction of infections will lead to serious consequences, but after a long(er) latency period. Furthermore, it should be kept in mind that in clinical trials, the quadrivalent vaccine was tested in fewer than 1200 girls 16 years and younger.1

In Germany, as in many other countries, HPV vaccines targeting two of 15 oncogenic2 HPV types are being positioned by pharmaceutical companies and universities based clinicians and scientists as a single though profoundly effective medical measure to eradicate a substantial proportion of the burden of disease indeed constituted by the occurrence of cervical cancer for the individual woman and her family. HPV vaccines primarily target individuals and in this case female minors and their parents, particular mothers. However, published data for periods beyond 2 years were not available in spring 2009 as to what fraction of cervical intraepithelial lesions (CIN) grade 2 or worse and cancer incidence, respectively, are indeed prevented in young girls not infected with any HPV type prior immunisation with a vaccine targeting HPV types 16 and 18. In spring 2006, an analysis of vaccine efficacy against CIN 2+ due to any HPV type among subgroup of girls/women (per protocol population) for all four vaccine-relevant HPV types showed an observed reduction of (only) 16.9% regarding these lesions3 (for a discussion of published efficacy data in Germany, see also Gerhardus et al4).
Yet, data were recently published on the impact of the quadrivalent vaccine on cervical disease due to non-vaccine HPV types in a subset of girls and women aged 16 and older participating in licensing trials and followed for up to 4 years.5

Thus, the efficacy of the licenced vaccines to prevent cervical cancer is unknown; in other words, it is unknown whether vaccinations are indeed a “magic bullet,” a term also used recently to re-evaluate menopausal hormone therapy, the benefits of which were not “magic” after all. Perhaps the magic of
female nature in this case is that most infections (approximately 90%) are dealt with very effectively and permanently in immunocompetent (young) women. Therefore, girls/women with HPV infections are highly unlikely to develop invasive cervical cancer. This is crucial risk information not transported affirmatively by various parties actively promoting HPV vaccination.6

HPV vaccinations do not deconstruct the multifactorial nature of cervical cancer deeply affecting (sexual) life, not only for girls and women and (their) mothers but also for boys, menand fathers. HPV infection is more than an individual risk to be managed by an individual. If exogenous or endogenous factors such as high parity, smoking or long-term use of oral contraceptives interact with both the central and strong effect of HPV, cervical cancer may develop.

Additional cofactors such as herpes simplex virus type 2, chlamydia trachomatis, and states of immunosuppression including infection with HIValso need consideration. It is beyond the scopeof this essay to address nutritional deficiencies, probably reflecting the socio-economic position of girls and women, not least in developing countries with by far the greatest burden of disease,7 and genetic susceptibility.

It was possible to reduce the impact of cervical cancer with the technology of screening utilising Pap smears worldwide. Presently, cervical cancer is the twelfth most frequent cancer in German females and accounts for approximately 6200 incident cases annually (data from the German Cancer Research Center: http://www.dkfz.de/en/krebsatlas/total/organ_e.html; updated 6 May 2009, accessed 12 August, 2009). In 1971, when the
incidence of cervical cancer was much higher, an annual free-ofcharge
Pap smear was introduced in the former West Germany for women 20 years and older.8 This deviates from internationally recommended screening intervals of 3 to 5 years. This “statutory early detection programme” is a self-referring opportunistic screening system, without invitations and without establishment of a registration system, and not least without any known
individual adherence of women. Thus, it is unknown which women attend services providing smears, and how often they do this within a given time interval. However, in Germany, a strong decline of both incidence and mortality by about 80% since the 1960s is evident.9

Martina Do¨ren
Correspondence to Professor Martina Do¨ren, Charite´-Universita¨tsmedizin Berlin, Campus Benjamin Franklin, Clinical Research Center of Women’s Health, Hindenburgdamm 30, Berlin D-12200, Germany; martina.doeren@charite.de

Competing interests None.

Provenance and peer review Commissioned; externally peer reviewed.
J Epidemiol Community Health 2010;64:103e104.
doi:10.1136/jech.2008.086959

Read Full Article

PG

Author: Leslie Carol Botha

Author, publisher, radio talk show host and internationally recognized expert on women's hormone cycles. Social/political activist on Gardasil the HPV vaccine for adolescent girls. Co-author of "Understanding Your Mood, Mind and Hormone Cycle." Honorary advisory board member for the Foundation for the Study of Cycles and member of the Society for Menstrual Cycle Research.