پیامدهایی برای طراحی واکسن
Abstract
1- Introduction
2- Methods
3- Results
4- Discussion
5- Conclusion
References
Abstract
Transmissible vaccines may provide a promising solution for improving the control of infectious disease, particularly zoonotic pathogens with wildlife reservoirs. Although it is well known that heterogeneity in pathogen transmission impacts the spread of infectious disease, the effects of heterogeneity on vaccine transmission are largely unknown. Here we develop and analyze a mathematical model that quantifies the potential benefits of a transmissible vaccine in a population where transmission is heterogeneous between two subgroups. Our results demonstrate that the effect of heterogeneity on the benefit of vaccine transmission largely depends on the vaccine design and the pattern of vaccine administration across subgroups. Specifically, our results show that in most cases a transmissible vaccine designed to mirror the transmission of the pathogen is optimal. If the vaccination effort can be preferentially biased towards a given subgroup, a vaccine with a pattern of transmission opposite to that of the pathogen can become optimal in some cases. To better understand the consequences of heterogeneity on the effectiveness of a transmissible vaccine in the real world, we parameterized our model using data from Sin Nombre virus in deer mice (Peromyscus maniculatus). The results of this analysis reveal that when a vaccination campaign is limited in vaccine availability, a traditional vaccine must be administered primarily to males for the spread of Sin Nombre virus to be prevented. In contrast, a transmissible vaccine remains effective even when it cannot be preferentially administered to males.
Introduction
Zoonoses, particularly those circulating in wildlife populations, are a primary source of pathogens that infect humans [1]. The burden of such pathogens on human populations can be profound, as demonstrated in the 2014–2015 West African Ebola virus epidemic. The virus was transmitted from wild animal populations such as fruit bats and apes [2], and resulted in over 11,000 human deaths and cost over 3.6 billion dollars [3]. Such outbreaks highlight the need to develop costeffective strategies that mitigate zoonotic spillover into human populations. One strategy for reducing the spillover potential of zoonoses is to decrease the prevalence of infectious disease within wildlife reservoir populations. Both culling [4] and mass vaccination [4,5] have been used to control pathogens in wildlife reservoir populations. Though both strategies have been successful in some cases [4], the costs of implementation and the difficulties of delivering vaccine to wild animals limit their scope of applicability [6]. Transmissible vaccines are a novel tool that might overcome some of these challenges, allowing for pathogen reduction or even the prevention of pathogen spread in wildlife reservoirs.