Penelope Gray1, Hanna Kann2, Ville N Pimenoff2,3,4, Tiina Eriksson5, Tapio Luostarinen6, Simopekka Vänskä7, Heljä-Marja Surcel8,9, Helena Faust2, Joakim Dillner2, Matti Lehtinen2,4,7,10. 1. Faculty of Social Sciences, Tampere University, Tampere, Finland. 2. Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden. 3. Oncology Data Analytics Program, Bellvitge Biomedical Research Institute (IDIBELL), Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Hospitalet de Llobregat, Barcelona, Spain. 4. FICAN Mid, Tampere, Finland. 5. Department of Research and Development, Tampere University Hospital, Tampere, Finland. 6. Finnish Cancer Registry, Helsinki, Finland. 7. Department of Infectious Disease Control and Vaccination, Finnish Institute for Health and Welfare, Helsinki, Finland. 8. Faculty of Medicine, University of Oulu, Oulu, Finland. 9. Biobank Borealis of Northern Finland, Oulu University Hospital, Oulu, Finland. 10. Infections and Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Abstract
BACKGROUND: Cervical cancer elimination through human papillomavirus (HPV) vaccination programs requires the attainment of herd effect. Due to its uniquely high basic reproduction number, the vaccination coverage required to achieve herd effect against HPV type 16 exceeds what is attainable in most populations. We have compared how gender-neutral and girls-only vaccination strategies create herd effect against HPV16 under moderate vaccination coverage achieved in a population-based, community-randomized trial. METHODS AND FINDINGS:In 2007-2010, the 1992-1995 birth cohorts of 33 Finnish communities were randomized to receive gender-neutral HPV vaccination (Arm A), girls-only HPV vaccination (Arm B), or no HPV vaccination (Arm C) (11 communities per trial arm). HPV16/18/31/33/35/45 seroprevalence differences between the pre-vaccination era (2005-2010) and post-vaccination era (2011-2016) were compared between all 8,022 unvaccinated women <23 years old and resident in the 33 communities during 2005-2016 (2,657, 2,691, and 2,674 in Arms A, B, and C, respectively). Post- versus pre-vaccination-era HPV seroprevalence ratios (PRs) were compared by arm. Possible outcome misclassification was quantified via probabilistic bias analysis. An HPV16 and HPV18 seroprevalence reduction was observed post-vaccination in the gender-neutral vaccination arm in the entire study population (PR16 = 0.64, 95% CI 0.10-0.85; PR18 = 0.72, 95% CI 0.22-0.96) and for HPV16 also in the herpes simplex virus type 2 seropositive core group (PR16 = 0.64, 95% CI 0.50-0.81). Observed reductions in HPV31/33/35/45 seroprevalence (PR31/33/35/45 = 0.88, 95% CI 0.81-0.97) were replicated in Arm C (PR31/33/35/45 = 0.79, 95% CI 0.69-0.90). CONCLUSIONS: In this study we only observed herd effect against HPV16/18 after gender-neutral vaccination with moderate vaccination coverage. With only moderate vaccination coverage, a gender-neutral vaccination strategy can facilitate the control of even HPV16. Our findings may have limited transportability to other vaccination coverage levels. TRIAL REGISTRATION: ClinicalTrials.gov number NCT00534638, https://clinicaltrials.gov/ct2/show/NCT00534638.
RCT Entities:
BACKGROUND: Cervical cancer elimination through human papillomavirus (HPV) vaccination programs requires the attainment of herd effect. Due to its uniquely high basic reproduction number, the vaccination coverage required to achieve herd effect against HPV type 16 exceeds what is attainable in most populations. We have compared how gender-neutral and girls-only vaccination strategies create herd effect against HPV16 under moderate vaccination coverage achieved in a population-based, community-randomized trial. METHODS AND FINDINGS: In 2007-2010, the 1992-1995 birth cohorts of 33 Finnish communities were randomized to receive gender-neutral HPV vaccination (Arm A), girls-only HPV vaccination (Arm B), or no HPV vaccination (Arm C) (11 communities per trial arm). HPV16/18/31/33/35/45 seroprevalence differences between the pre-vaccination era (2005-2010) and post-vaccination era (2011-2016) were compared between all 8,022 unvaccinated women <23 years old and resident in the 33 communities during 2005-2016 (2,657, 2,691, and 2,674 in Arms A, B, and C, respectively). Post- versus pre-vaccination-era HPV seroprevalence ratios (PRs) were compared by arm. Possible outcome misclassification was quantified via probabilistic bias analysis. An HPV16 and HPV18 seroprevalence reduction was observed post-vaccination in the gender-neutral vaccination arm in the entire study population (PR16 = 0.64, 95% CI 0.10-0.85; PR18 = 0.72, 95% CI 0.22-0.96) and for HPV16 also in the herpes simplex virus type 2 seropositive core group (PR16 = 0.64, 95% CI 0.50-0.81). Observed reductions in HPV31/33/35/45 seroprevalence (PR31/33/35/45 = 0.88, 95% CI 0.81-0.97) were replicated in Arm C (PR31/33/35/45 = 0.79, 95% CI 0.69-0.90). CONCLUSIONS: In this study we only observed herd effect against HPV16/18 after gender-neutral vaccination with moderate vaccination coverage. With only moderate vaccination coverage, a gender-neutral vaccination strategy can facilitate the control of even HPV16. Our findings may have limited transportability to other vaccination coverage levels. TRIAL REGISTRATION: ClinicalTrials.gov number NCT00534638, https://clinicaltrials.gov/ct2/show/NCT00534638.
Authors: Francesca Pesola; Christopher Mathews; Matejka Rebolj; David Mesher; Kate Soldan; Henry Kitchener Journal: Br J Cancer Date: 2022-03-26 Impact factor: 9.075
Authors: Matti Lehtinen; Dan Apter; Tiina Eriksson; Katja Harjula; Mari Hokkanen; Kari Natunen; Pekka Nieminen; Jorma Paavonen; Johanna Palmroth; Tiina Petäjä; Eero Pukkala; Simopekka Vänskä; Brigitte Cheuvart; Maaria Soila; Dan Bi; Frank Struyf Journal: Cancer Med Date: 2021-09-27 Impact factor: 4.452