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Computational and Mathematical Methods in Medicine
Volume 2014, Article ID 542923, 8 pages
http://dx.doi.org/10.1155/2014/542923
Research Article

Dynamics of High-Risk Nonvaccine Human Papillomavirus Types after Actual Vaccination Scheme

1Departamento de Matemáticas, Facultad de Ciencias, UNAM. Avenida Universidad 3000, Circuito Exterior S/N Delegación Coyoacán, C.P. 04510 Ciudad Universitaria, D.F., Mexico
2Centro de Ciencias de la Complejidad (C3), Torre de Ingeniería, UNAM. Avenida Universidad 3000, Circuito Exterior S/N Delegación Coyoacán, C.P. 04510 Ciudad Universitaria, D.F., Mexico
3Hospital General de México, Dr Balmis No. 148. Col. Doctores C.P. 06726 México, D.F., Mexico
4Unidad Académica de Matemáticas, Universidad Autónoma de Guerrero, Avenida Lázaro Cárdenas S/N, Ciudad Universitaria, C.P. 39090 Chilpancingo, GRO, Mexico

Received 1 January 2014; Accepted 7 March 2014; Published 3 April 2014

Academic Editor: Edelmira Valero

Copyright © 2014 Raúl Peralta et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Human papillomavirus (HPV) has been identified as the main etiological factor in the developing of cervical cancer (CC). This finding has propitiated the development of vaccines that help to prevent the HPVs 16 and 18 infection. Both genotypes are associated with 70% of CC worldwide. In the present study, we aimed to determine the emergence of high-risk nonvaccine HPV after actual vaccination scheme to estimate the impact of the current HPV vaccines. A SIR-type model was used to study the HPV dynamics after vaccination. According to the results, our model indicates that the application of the vaccine reduces infection by target or vaccine genotypes as expected. However, numerical simulations of the model suggest the presence of the phenomenon called vaccine—induced pathogen strain replacement. Here, we report the following replacement mechanism: if the effectiveness of cross-protective immunity is not larger than the effectiveness of the vaccine, then the high-risk nonvaccine genotypes emerge. In this scenario, further studies of infection dispersion by HPV are necessary to ascertain the real impact of the current vaccines, primarily because of the different high-risk HPV types that are found in CC.