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Impact of vaccination on 14 high-risk HPV type infections: a mathematical modelling approach.

Vänskä S, Auranen K, Leino T, Salo H, Nieminen P, Kilpi T, Tiihonen P, Apter D, Lehtinen M - PLoS ONE (2013)

Bottom Line: The analysis disclosed the important role of persistent infections in hrHPV epidemiology, provided further evidence for a significant natural immunity, and demonstrated the dependence of transmission probability estimates on the model structure.In males, the reduction will be 42% in the hrHPV prevalence solely by the herd effect from the 80% coverage in girls.On the other hand, any herd effects in older unvaccinated cohorts were minor.

View Article: PubMed Central - PubMed

Affiliation: Department of Vaccination and Immune Protection, National Institute for Health and Welfare (THL), Helsinki, Finland. simopekka.vanska@thl.fi

ABSTRACT
The development of high-risk human papillomavirus (hrHPV) infection to cervical cancer is a complicated process. We considered solely hrHPV infections, thus avoiding the confounding effects of disease progression, screening, and treatments. To analyse hrHPV epidemiology and to estimate the overall impact of vaccination against infections with hrHPVs, we developed a dynamic compartmental transmission model for single and multiple infections with 14 hrHPV types. The infection-related parameters were estimated using population-based sexual behaviour and hrHPV prevalence data from Finland. The analysis disclosed the important role of persistent infections in hrHPV epidemiology, provided further evidence for a significant natural immunity, and demonstrated the dependence of transmission probability estimates on the model structure. The model predicted that vaccinating girls at 80% coverage will result in a 55% reduction in the overall hrHPV prevalence and a higher 65% reduction in the prevalence of persistent hrHPV infections in females. In males, the reduction will be 42% in the hrHPV prevalence solely by the herd effect from the 80% coverage in girls. If such high coverage among girls is not reached, it is still possible to reduce the female hrHPV prevalence indirectly by the herd effect if also boys are included in the vaccination program. On the other hand, any herd effects in older unvaccinated cohorts were minor. Limiting the epidemiological model to infection yielded improved understanding of the hrHPV epidemiology and of mechanisms with which vaccination impacts on hrHPV infections.

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Related in: MedlinePlus

The Pattern of Sexual Contacts in Finland.Upper panel: the age-specific annual mean numbers of new sexual partners by lifetime partner number with the observed numbers (asterisks). Lower panel: the age-specific stratification of the population by lifetime partner number and the corresponding data (asterisks).
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pone-0072088-g002: The Pattern of Sexual Contacts in Finland.Upper panel: the age-specific annual mean numbers of new sexual partners by lifetime partner number with the observed numbers (asterisks). Lower panel: the age-specific stratification of the population by lifetime partner number and the corresponding data (asterisks).

Mentions: The new partner acquisition rate and the corresponding partner number distribution (Figure 2, Figures S1–S3 in File S1) were estimated from the School Health Promotion (SHP) Study 2008–2009 [21], the FINSEX 2007 study [22], and national data on age at marriage [23]. The biannual SHP study covers over half of the 14–18 years old population in Finland. FINSEX 2007 is a population based sampling survey of 2590 adults, and the register-based marriage statistics includes all new marriages in Finland in 2008.


Impact of vaccination on 14 high-risk HPV type infections: a mathematical modelling approach.

Vänskä S, Auranen K, Leino T, Salo H, Nieminen P, Kilpi T, Tiihonen P, Apter D, Lehtinen M - PLoS ONE (2013)

The Pattern of Sexual Contacts in Finland.Upper panel: the age-specific annual mean numbers of new sexual partners by lifetime partner number with the observed numbers (asterisks). Lower panel: the age-specific stratification of the population by lifetime partner number and the corresponding data (asterisks).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756967&req=5

pone-0072088-g002: The Pattern of Sexual Contacts in Finland.Upper panel: the age-specific annual mean numbers of new sexual partners by lifetime partner number with the observed numbers (asterisks). Lower panel: the age-specific stratification of the population by lifetime partner number and the corresponding data (asterisks).
Mentions: The new partner acquisition rate and the corresponding partner number distribution (Figure 2, Figures S1–S3 in File S1) were estimated from the School Health Promotion (SHP) Study 2008–2009 [21], the FINSEX 2007 study [22], and national data on age at marriage [23]. The biannual SHP study covers over half of the 14–18 years old population in Finland. FINSEX 2007 is a population based sampling survey of 2590 adults, and the register-based marriage statistics includes all new marriages in Finland in 2008.

Bottom Line: The analysis disclosed the important role of persistent infections in hrHPV epidemiology, provided further evidence for a significant natural immunity, and demonstrated the dependence of transmission probability estimates on the model structure.In males, the reduction will be 42% in the hrHPV prevalence solely by the herd effect from the 80% coverage in girls.On the other hand, any herd effects in older unvaccinated cohorts were minor.

View Article: PubMed Central - PubMed

Affiliation: Department of Vaccination and Immune Protection, National Institute for Health and Welfare (THL), Helsinki, Finland. simopekka.vanska@thl.fi

ABSTRACT
The development of high-risk human papillomavirus (hrHPV) infection to cervical cancer is a complicated process. We considered solely hrHPV infections, thus avoiding the confounding effects of disease progression, screening, and treatments. To analyse hrHPV epidemiology and to estimate the overall impact of vaccination against infections with hrHPVs, we developed a dynamic compartmental transmission model for single and multiple infections with 14 hrHPV types. The infection-related parameters were estimated using population-based sexual behaviour and hrHPV prevalence data from Finland. The analysis disclosed the important role of persistent infections in hrHPV epidemiology, provided further evidence for a significant natural immunity, and demonstrated the dependence of transmission probability estimates on the model structure. The model predicted that vaccinating girls at 80% coverage will result in a 55% reduction in the overall hrHPV prevalence and a higher 65% reduction in the prevalence of persistent hrHPV infections in females. In males, the reduction will be 42% in the hrHPV prevalence solely by the herd effect from the 80% coverage in girls. If such high coverage among girls is not reached, it is still possible to reduce the female hrHPV prevalence indirectly by the herd effect if also boys are included in the vaccination program. On the other hand, any herd effects in older unvaccinated cohorts were minor. Limiting the epidemiological model to infection yielded improved understanding of the hrHPV epidemiology and of mechanisms with which vaccination impacts on hrHPV infections.

Show MeSH
Related in: MedlinePlus