A stochastic SIR epidemic dynamic model with distributed-time-delay, for a two-scale dynamic population is derived. The distributed time delay is the varying naturally acquired immunity period of the removal class of individuals who have recovered from the infection, and have acquired natural immunity to the disease. We investigate the stochastic asymptotic stability of the disease free equilib...

Resistance and susceptibility to Listeria monocytogenes in mice was found to be related to (i) the innate ability of the nonimmune macrophages to kill or inhibit the growth of the organism during the first 24 to 48 h after infection, and (ii) the time of onset of acquired cell-mediated resistance. Resistant C57Bl/6 mice were 10 times more efficient than susceptible BALB/c mice at suppressing th...

pumpkin, as a dietary plant, has been used in traditional medicine around the world. in addition, during the last decade, antidiabetic, antihypertensive, antitumor, intestinal antiparasitic, antibacterial, anti hypercholesterolemia, anti-inflammatory, immunomodulatory and analgic effects of pumpkin has been reported. the aim of the present study was to determine the effects of different extract...

Dendritic cells (DC) are required for priming antigen-specific T cells and acquired immunity to many important human pathogens, including Mycobacteriuim tuberculosis (TB) and influenza. However, inappropriate priming of auto-reactive T cells is linked with autoimmune disease. Understanding the molecular mechanisms that regulate the priming and activation of naïve T cells is critical for develop...

Most mathematical models for acquired immunity to Plasmodium falciparum consider effects of immunity on duration of infection and infectiousness, but do not consider the most evident effect of immunity, which is to reduce parasite densities. Few attempts have been made to fit such models to field data. We propose a stochastic simulation model to predict the distributions of P. falciparum parasi...

Acquired immunity is known to be a key modulator of the dynamics of many helminth parasites in domestic and human host populations, but its relative importance in natural populations is more controversial. A detailed long-term dataset on the gastrointestinal nematode Trichostrongylus retortaeformis in a wild population of European rabbits (Oryctolagus cuniculus) shows clear evidence of seasonal...

The immunobiology underlying the slow acquisition of skin immunity to group A streptococci (GAS), is not understood, but attributed to specific virulence factors impeding innate immunity and significant antigenic diversity of the type-specific M-protein, hindering acquired immunity. We used a number of epidemiologically distinct GAS strains to model the development of acquired immunity. We show...

tetanus can be only prevented by vaccination because immunity against this disease is rarely acquired, even by natural infections. to maintain long-term protective immunity against tetanus, booster immunization is essential for adolescents and adults. most hospitalized cases and virtually all deaths occur in people over 60 years of age. the purpose of this study was to investigate the degree of...

The most celebrated component of the vertebrate immune system is the acquired response in which memory cells established during primary infection enhance the proliferation of antibodies during secondary infection. Additionally, the strength of vertebrate acquired immune responses varies dramatically depending on the infecting pathogen species or on the pathogen genotype within species. Because ...