Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptib...Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptible individuals in population is as the detection threshold value. By the Poincaré map, theory of differential inequalities and differential equation geometry, the existence and orbital stability of the disease-free periodic solution are discussed. Theoretical results show that by state-dependent pulse vaccination we can make the proportion of infected individuals tend to zero, and control the transmission of disease in population.展开更多
This article focuses on the study of an age structured SEIRS epidemic model with a vaccination program when the total population size is not kept at constant. We first give the explicit expression of the reproduction ...This article focuses on the study of an age structured SEIRS epidemic model with a vaccination program when the total population size is not kept at constant. We first give the explicit expression of the reproduction number in the presence of vaccine ( is the exponent of growth of total population), and show that the infection-free steady state is linearly stable if and unstable if , then we apply the theoretical results to vaccination policies to determine the optimal age or ages at which an individual should be vaccinated. It is shown that the optimal strategy can be either one- or two-age strategies.展开更多
Both HIV and COVID-19 infections show that the centuries-old scientifically established epidemiological rules are still valid today, but they have to be applied in time and in a correct manner. Furthermore, when incom...Both HIV and COVID-19 infections show that the centuries-old scientifically established epidemiological rules are still valid today, but they have to be applied in time and in a correct manner. Furthermore, when incompetent funded “rights defenders” or political organizations referring to human rights have spread lies and have spoken against the experts-created epidemiological rules as well as the acceptance of vaccination, they have not only cheated everybody but they could also be accused by the crime of endangering of great mass of people which action can cause occasionally death also! It has to be also stated that the interests and rights of the total population are always over that of a single person and also realized that all pathogens live their own life among us according to their determinacy independently from our rights and interests!展开更多
文摘Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptible individuals in population is as the detection threshold value. By the Poincaré map, theory of differential inequalities and differential equation geometry, the existence and orbital stability of the disease-free periodic solution are discussed. Theoretical results show that by state-dependent pulse vaccination we can make the proportion of infected individuals tend to zero, and control the transmission of disease in population.
基金Supported by the NSFC (No.10371105) and the NSF of Henan Province (No.0312002000No.0211044800)
文摘This article focuses on the study of an age structured SEIRS epidemic model with a vaccination program when the total population size is not kept at constant. We first give the explicit expression of the reproduction number in the presence of vaccine ( is the exponent of growth of total population), and show that the infection-free steady state is linearly stable if and unstable if , then we apply the theoretical results to vaccination policies to determine the optimal age or ages at which an individual should be vaccinated. It is shown that the optimal strategy can be either one- or two-age strategies.
文摘Both HIV and COVID-19 infections show that the centuries-old scientifically established epidemiological rules are still valid today, but they have to be applied in time and in a correct manner. Furthermore, when incompetent funded “rights defenders” or political organizations referring to human rights have spread lies and have spoken against the experts-created epidemiological rules as well as the acceptance of vaccination, they have not only cheated everybody but they could also be accused by the crime of endangering of great mass of people which action can cause occasionally death also! It has to be also stated that the interests and rights of the total population are always over that of a single person and also realized that all pathogens live their own life among us according to their determinacy independently from our rights and interests!
