Since May 2009, the pandemic influenza A(H1N1) virus has been spreading throughout the world. Epidemiological data indicate that the elderly are underrepresented among the ill individuals. Approximately 1,000 serum specimens collected in Finland in 2004 and 2005 from individuals born between 1909 and 2005, were analysed by haemagglutination-inhibition test for the presence of antibodies against...

Antibody cross-reactivity to the influenza A(H3N2) variant virus recently reported in the United States, was investigated in Norwegian sera. Seroprevalence was 40% overall, and 71% in people born between 1977 and 1993. The most susceptible age groups were children and people aged around 50 years. The high immunity in young adults is likely to be due to strong priming infection with similar viru...

We analyze models for the evolutionary dynamics of viral or other infectious agents within a host. We study how the invasion of a new strain affects the composition and diversity of the viral population. We show that--under strain-specific immunity--the equilibrium abundance of uninfected cells declines during viral evolution. In addition, for cytotoxic immunity the absolute force of infection,...

Spontaneous active immunity to the phenomenon of local skin reactivity to bacterial filtrates has been demonstrated. In one experiment, the immunity was non-specific, while in others it appeared limited to one or two bacterial species. Intradermal vaccination of rabbits with bacterial filtrates induced active immunity to the phenomenon. The specificity of this immunity was tested with graded am...

Prostaglandins not only have a role in inflammation, but may also be involved as mediators in the immune response. Drugs which affect prostaglandin synthesis may therefore be potential tools with which to modulate disturbed immunity. These possibilities are discussed with reference to immunity in leprosy, and in particular reversal reactions.

Evaluation of cellular immunity in bovine brucella seropositive animals has been preformed , using one invitro test , the leucocytes migration test " LMIT " and one invivo test , the skin reaction by using prepared brucellin form Brucella abortus strain RR51 .All these tests showed significant reactions and proved to be reliable tests for proper appreciation of cellular immunity in bovine bruce...

Reactions of innate immunity include phagocytosis, the production and activity of cytokines, chemokines, and adhesion molecules, the killing of infected or changed cells by NK cells and complement activated by natural lectins, and the cytokine-dependent resistance of leukocytes to viral infection. All these mechanisms maintain innate immunity. Deficiency in this immunity is sometimes accompanie...