FC 19-11Effects of vaccination on the epidemiology of HPV67 in a Belgian routine setting

02. Epidemiology and natural history
S. Nouws 1, V. Hutse 2, N. Redzic 1, L. De Baere 3, D. Vanden Broeck 1, I. Benoy 1, J.P. Bogers 1.
1Laboratory of Molecular Pathology, AML, Antwerp, Belgium; National Reference Centre for HPV, Brussels, Belgium; AMBIOR, Laboratory for Cell Biology & Histology, University of Antwerp, Antwerp, Belgium (Belgium) (Belgium), 2Service of Viral diseases, National Reference Centre for Measels, Bof, Rubella, HPV, WIV-ISP, Brussels, Belgium (Belgium), 3Laboratory of Molecular Pathology, AML, Antwerp, Belgium; National Reference Centre for HPV, Brussels, Belgium (Belgium) (Belgium)

Background / Objectives

HPV vaccination programs with the HPV bivalent (HPV16/18) vaccine (Cervarix®, GlaxoSmithKline Biologicals, United Kingdom) or the recombinant HPV quadrivalent (HPV16/18/6/11) vaccine (Gardasil®, Merck & Co, Inc., USA) have been implemented in the majority of industrialized countries. According to the International Agency of Research on Cancer (IARC, World Health Organization, France) HPV67 is subdivided as a possible high-risk HPV. This study was performed to broaden the epidemiological knowledge of HPV67 in a Belgian Routine setting, and to evaluate the potential influence of vaccination status on its prevalence.


Methods

In total, 478,822 samples were evaluated with the Riatol qPCR assay. Self-reported vacination status was known for 376,905 samples. A subset of 22,878 women reported to be vaccinated.


Results

HPV67 is found in 1.23% (95% CI: 1.20%-1.26%) of the screening population, with a significant (p<0.001, Pearson's Chi Square Test) higher prevalence in the diagnostic population 4.16% (95% CI: 4.04%-4.28%). In the screening population, multiple infections with other HPV genotype(s) occur in 51.36% (95% CI: 49.96%-52.76%). The most prevalent coinfections involve HPV39/51/16/59. Furthermore, HPV67 is associated with HPV18/39/31 in coinfections within the diagnostic population. HPV67 is significantly (p=0.021, Pearson's Chi Square Test) more prevalent in vaccinated women (3.36%; 95% CI: 3.06%-3.68%), compared to the non-vaccinated population (2.94%; 95% CI: 2.75%-3.14%). Similar results are obtained for other HPV types. In the proportion of women vaccinated with Gardasil® (0.13%; 95% CI: 0.11%-0.14%) vs Cervarix® (0.11%; 95% CI: 0.08%-0.13%) no significant differences (p=0.228, Pearson's Chi Square Test) are found.

 


Conclusion

The overall prevalence of HPV67 in Belgian women is 1.86%. The changing coinfection patterns between screening and diagnostic populations should be topic of further research. Specific non-HPV16/18 genotypes are observed to be significantly more prevalent in vaccinated women, irrespective of vaccine type. These data hypothesize a continuous HPV genotype shift. In addition, HPV31/33 (together with HPV16 in α9-species) and HPV45/68 (with HPV18 in α7-species) display a significant reduction in prevalence in the vaccinated population. Phylogenetic related HPV genotypes share similar capsid epitopes, potentially eliciting cross-reactive immune responses after vaccination. Our findings indicate that selected possible high-risk HPV types as HPV67 are more frequently found in vaccinated women. It is therefore warranted to perform close surveillance on the transforming potential of these types, including HPV67.


References