A mathematical model for human papillomavirus vaccination strategies in a random network

Abstract

[EN] In this paper, we consider a random network model for sexual contacts in a population developed from real statistical data in order to assess vaccination policies against sexually transmitted diseases (STDs). The model is constructed by imposing a constraint requiring that individuals of a given sex, in a given age group, would have an average connectivity as that obtained in statistic surveys.

In this model, the disease is transmitted stochastically according to a set of probability of infection parameters that depend on the age group. We are, in particular, interested on human papillomavirus (HPV) infections, characterized by a high infectivity and prevalence among the population. By building a network of up to 1000 nodes, we are able to obtain a stationary state under the assumption of constant population. Starting with this model, we will simulate several scenarios for vaccination against HPV by using the recent HPV ninevalent vaccine, which prevents against several oncogenic genotypes of the virus. Three different scenarios are simulated: only girls are vaccinated, only boys are vaccinated, or both sexes are vaccinated (gender neutral vaccination). Important levels of herd immunity are observed if only one sex is vaccinated and the scenario in which only boys are vaccinated is plausible in terms of cost-effectiveness. However, the serious consequences for women infected with oncogenic genotypes speak against this latter scenario. Conclusions about global vaccination programs are finally discussed in terms of our model