Efficacy of Vaccination against HPV Infections to Prevent Cervical Cancer in France: Present Assessment and Pathways to Improve Vaccination Policies

Laboratoire Mathématiques Appliquées à Paris 5, Centre National de la Recherche Scientifique Unité Mixte de Recherche n°8145, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
PLoS ONE (Impact Factor: 3.23). 03/2012; 7(3):e32251. DOI: 10.1371/journal.pone.0032251
Source: PubMed


Seventy percent of sexually active individuals will be infected with Human Papillomavirus (HPV) during their lifetime. These infections are incriminated for almost all cervical cancers. In France, 3,068 new cases of cervical cancer and 1,067 deaths from cervical cancer occurred in 2005. Two vaccines against HPV infections are currently available and vaccination policies aim to decrease the incidence of HPV infections and of cervical cancers. In France, vaccine coverage has been reported to be low.
We developed a dynamic model for the heterosexual transmission of Human Papillomavirus types 16 and 18, which are covered by available vaccines. A deterministic model was used with stratification on gender, age and sexual behavior. Immunity obtained from vaccination was taken into account. The model was calibrated using French data of cervical cancer incidence.
In view of current vaccine coverage and screening, we expected a 32% and 83% reduction in the incidence of cervical cancers due to HPV 16/18, after 20 years and 50 years of vaccine introduction respectively. Vaccine coverage and screening rates were assumed to be constant. However, increasing vaccine coverage in women or vaccinating girls before 14 showed a better impact on cervical cancer incidence. On the other hand, performing vaccination in men improves the effect on cervical cancer incidence only moderately, compared to strategies in females only.
While current vaccination policies may significantly decrease cervical cancer incidence, other supplementary strategies in females could be considered in order to improve vaccination efficacy.

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Available from: Stephan Clémençon
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    • "Studies suggest that 75% of sexually active people will be infected with HPV at some point during their lives [18]. However, acceptance of the HPV vaccination is still lacking, both in Western communities [19,20] and non-Western communities like Hong Kong [16,17]. Hence, understanding women’s perceptions about HPV and the HPV vaccine is important to encourage more comprehensive vaccination coverage. "
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    ABSTRACT: Background Significant others are noted to be remarkable influences in modelling children’s and young people’s health perceptions and their adoption of health behaviour. The vaccinations which a child receives are shown to be significantly influenced by his or her parents. However, there is a paucity of Chinese-based studies. When discussing the Human Papillomavirus (HPV) vaccine, very few studies examine the perceptions of Chinese parents regarding the vaccine as a preventive health measure, and even fewer examine how these perceptions of the vaccine and sexual values influence their motivations in encouraging their children to be vaccinated. In view of the literature gap, this article investigates the perceptions of Hong Kong mothers in regard to vaccinating their daughters against HPV in Hong Kong. Methods A qualitative research approach with individual semi-structured interviews was conducted with 35 mothers aged 30 to 60 years old with daughter(s) between 9 and 17 years old. Results Six connected themes emerged. The participants commonly perceived the HPV vaccination as being unnecessary for their daughters in view of their young age. They worried that it would encourage their daughters to engage in premarital sex, and perceived the vaccination to be potentially harmful to health. Also, their low perceived risk of HPV in addition to the lack of reassurance from their health care providers failed to convince the participants that the vaccination was important for their daughters’ health. Finally, the participants found the vaccine to be expensive and perceived it to have little protection value in comparison to other optional vaccines. Conclusion The sampled mothers did not have a positive perception of the HPV vaccine. The cultural association between receiving the vaccination and premarital sex was prevalent. Bounded by their cultural values, the participants also had many misconceptions regarding the vaccine and the transmission of HPV, which discouraged them from having their daughters vaccinated. Furthermore, a lack of support from health care providers and the government health authorities concerning HPV vaccination failed to provide confidence and reassurance to mothers, and conveyed a meaning to these mothers that HPV vaccine is relatively unimportant.
    Full-text · Article · Jun 2014 · BMC Women's Health
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    • "We did not assume that individuals who cleared HPV infection developed natural immunity against HPV. This approach of natural history for HPV infections has been used in other HPV models (Myers et al., 2000; Goldie et al., 2003; Kulasingam and Myers, 2003; Sanders and Taira, 2003; Goldie et al., 2004; Taira et al., 2004; Ribassin-Majed et al., 2012), whereas some other published models assumed natural immunity against HPV using Susceptible-Infected-Removed (S-I-R) structure (Elbasha et al., 2010). Existence and length of natural immunity after HPV clearance is uncertain and not biologically proved. "
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    ABSTRACT: Human papillomavirus (HPV) 16 and 18 are found to be involved in 80% of anal cancers. Two vaccines against HPV infections are currently available, and vaccination policies aim to decrease mainly, incidence of cervical cancers. Moreover, an impact of HPV vaccination on the incidence of anal cancer can also be expected. Our aim was to assess the potential benefits of HPV vaccination on the occurrence of female anal cancer in France. We developed a dynamic model for the heterosexual transmission of HPV and its progression to anal cancer in women. The model was calibrated using French data of anal cancer incidence. Considering vaccine coverage observed at the launch of vaccination campaign in France, reductions of 55 and 85% in the incidence of anal cancers due to HPV 16/18 are to be expected in French women 30 and 50 years after vaccine introduction, respectively. In case of a significant decrease in vaccine coverage, a dramatic reduction in the impact of HPV vaccination on female anal cancers would be observed. The number of anal cancer cases in French women is therefore expected to decrease significantly in 30 years, assuming sustained HPV vaccine coverage.
    Full-text · Article · May 2012
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    ABSTRACT: Most of molecules and cells involved in both types, innate and adaptive immunity are present within the feminine genital tract. This article attempts to list some of the various actors involved in these immunities, essentially at the vaginal level and to illustrate their implications in the most frequent pathologies. Among these molecules: defensins, collectins lysozyme, lactoferrin, calprotectin, SLP1, HSP and many others as well as Toll receptors and immunoglobulins (IgG and IgA) play a major role. Epithelial cells, antigen presenting cells, lymphocytes T, B, NK also contribute efficiently to the defenses in a coordinated way partially under the influence of sex hormones. The therapeutic perspectives, of which vaccines are briefly mentioned.
    No preview · Article · Sep 2012 · Journal de Gynécologie Obstétrique et Biologie de la Reproduction
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