Abstract
Human papillomavirus (HPV)
prevalence varies widely worldwide. We used a transmission model to show links
between age-specific sexual patterns and HPV vaccination effectiveness. We
considered rural India and the United States as examples of 2 heterosexual populations
with traditional age-specific sexual behavior and gender-similar age-specific
sexual behavior, respectively.
We simulated these populations by using
age-specific rates of sexual activity and age differences between sexual
partners and found that transitions from traditional to gender-similar sexual
behavior in women <35 years of age can result in increased (2.6-fold in our
study) HPV16 prevalence.
Our model shows that reductions in HPV16 prevalence
are larger if vaccination occurs in populations before transitions in sexual
behavior and that increased risk for HPV infection attributable to transition
is preventable by early vaccination. Our study highlights the importance of
using time-limited opportunities to introduce HPV vaccination in traditional
populations before changes in age-specific sexual patterns occur.
Below: Figure
1.
Relative reduction of prevalence of human papillomavirus type 16 at
postvaccination equilibrium (i.e., 70 years after the introduction of
vaccination) attributable to vaccination among women 20–34 years of age after
vaccination of 11-year-old girls or 11-year-old girls and boys, by coverage and
a population’s age-related sexual behavior. A) 30% vaccine coverage; B) 50%
vaccine coverage. Traditional sexual behavior indicates a population in which genders
have different age-specific sexual activity rates and a wide gap
in ages (e.g., an average of 5.6 years, as observed in India) of
spouses or cohabitating sexual partners. Gender-similar sexual
behavior indicates a population in which genders have similar
age-specific sexual activity rates and a narrow gap in ages (e.g., an
average of 2.1 years, as observed in the United States) of spouses or
cohabitating sexual partners.
Below: Figure
2.
Changes in prevalence of human papillomavirus type 16 among women 20–34 years
of age in relation to the number of years since the beginning of a population’s
transition from traditional to gender-similar age-related sexual behavior and
the introduction of vaccination among 11-year-old girls (with assumption of 70%
coverage) before and after transition. Shaded area shows an assumption of a
15-year transition period. Arrows show approximate timing of vaccination
occurring before or after a transition has occurred. Traditional sexual
behavior indicates a population in which genders have different age-specific
sexual activity rates and a wide gap in ages (e.g., an average of 5.6
years, as observed in India) of spouses or cohabitating sexual partners.
Gender-similar sexual behavior indicates a population in which genders have
similar age-specific sexual activity rates and a narrow gap in ages
(e.g., an average of 2.1 years, as observed in the United States) of
spouses or cohabitating sexual partners.
Full article at: http://goo.gl/p4LtBo
By:
Author affiliations: International Agency for Research
on Cancer, Lyon, France (I. Baussano, F. Lazzarato, S. Franceschi); University
of Turin, Turin, Italy (F. Lazzarato); University of Piemonte Orientale
Avogadro, Novara, Italy (F. Lazzarato); Centre de Recherche du Centre
Hospitalier Universitaire, Québec City, Québec, Canada (M. Brisson); Université
Laval, Québec City (M. Brisson); Imperial College, London, UK (M. Brisson)
More at: https://twitter.com/hiv_insight
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