By: Professor Martina Doren
Originally published February 2010
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 oncogenic(2) 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 lesions(3) (for a discussion of published efficacy data in Germany, see also Gerhardus et al(4).
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 immune-competent 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)