A major impediment to tuberculosis (TB) vaccine development is the lack of reliable correlates of immune protection or biomarkers that would predict vaccine efficacy. Gamma interferon (IFN-γ) produced by CD4(+) T cells and, recently, multifunctional CD4(+) T cells secreting IFN-γ, tumor necrosis factor (TNF), and interleukin-2 (IL-2) have been used in vaccine studies as a measurable immune para...

We previously reported that DNA vaccination was able to elicit cellular immune responses and partial protection against Chlamydia trachomatis infection. However, DNA immunization alone did not generate immune responses or protection as great as that induced by using live organisms. In this study, we evaluated the immunologic effects of a combinational vaccination approach using C. trachomatis m...

Most of the current security systems do not provide adequate level of protection against ever-increasing threats. The main reason for their failure is the use of point solutions to protect hosts and reactive approach against intrusions. We studied human immune system, which survives under dynamic changing conditions and provides protection against biological viruses and bacteria. By taking immu...

Stable spatial distribution of porcine reproductive and respiratory syndrome (PRRSV)-1 subtypes in Europe is accompanied by a strong population immunity induced by local PRRSV strains. In the present study, it was examined if the immunity induced by three West European subtype 1 PRRSV strains (2007 isolate 07V063 and 2013 isolates 13V091 and 13V117) offers protection against the highly virulent...

Drosophila melanogaster, like other invertebrates, relies solely on its innate immune response to fight invading microbes; by definition, innate immunity lacks adaptive characteristics. However, we show here that priming Drosophila with a sublethal dose of Streptococcus pneumoniae protects against an otherwise-lethal second challenge of S. pneumoniae. This protective effect exhibits coarse spec...

This paper attempts to summarize current knowledge about immune responses to vaccines that correlate with protection. Although the immune system is redundant, almost all current vaccines work through antibodies in serum or on mucosa that block infection or bacteremia/viremia and thus provide a correlate of protection. The functional characteristics of antibodies, as well as quantity, are import...

Immunity induced by the 19-kDa fragment of Plasmodium yoelii merozoite surface protein 1 (MSP1(19)) is dependent on high titers of specific antibodies present at the time of challenge and a continuing active immune response postinfection. However, the specificity of the active immune response postinfection has not been defined. In particular, it is not known whether anti-MSP1(19) antibodies tha...

Background: Toll like receptors play a major role in immune responses against Leishmania parasites. Objective: To evaluate the efficacy of vaccination with live attenuated L. major and TLR4 agonist in protection against L. major infection. Methods: Attenuated L. major was prepared by continuous sub-culturing of the parasite. A total of 90 mice were assigned to 9 groups including 6 groups of BAL...

The success of many vaccines relies on their association with selected adjuvants in order to increase their immunogenicity and ensure long-term protection. Propolis is a natural compounds, are mostly known for their immunostimulatory  properties. In this study the adjuvant effects of propolis in combination with formalin-killed A. hydrophila vaccine in Common carp (Cyprinus carpio) were evaluat...

Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least so...