Thermostable Cross-Protective Subunit Vaccine against Brucella Species

Abstract

A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 ؋ 10 5 CFU), and a single injection of 1 g of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation.

Phage-fused epitopes fromLeishmania infantumused as immunogenic vaccines confer partial protection againstLeishmania amazonensisinfection

“…The concept of universal vaccines is chiefly based on the presence of common antigens among pathogens and on the ability of properly formulated vaccines to elicit cross-protective adaptive immunity. In this sense, genomics is fast expanding the list of common proteins among organisms (Pizza et al 2000;Kanduc et al 2008;Real et al 2013), and has proven to be useful in selecting common antigens for vaccine development against diseases, such as brucellosis (Cherwonogrodzky et al 2014), salmonellosis (Heithoff et al 2015) and encephalitis (Lobigs and Diamond, 2012). In this sense, genomics is fast expanding the list of common proteins among organisms (Pizza et al 2000;Kanduc et al 2008;Real et al 2013), and has proven to be useful in selecting common antigens for vaccine development against diseases, such as brucellosis (Cherwonogrodzky et al 2014), salmonellosis (Heithoff et al 2015) and encephalitis (Lobigs and Diamond, 2012).…”

“…In this sense, genomics is fast expanding the list of common proteins among organisms (Pizza et al . 2000; Kanduc et al 2008; Real et al 2013), and has proven to be useful in selecting common antigens for vaccine development against diseases, such as brucellosis (Cherwonogrodzky et al 2014), salmonellosis (Heithoff et al . 2015) and encephalitis (Lobigs and Diamond, 2012).…”

“…Support for antigenic commonality among pathogens derives from both indirect and direct evidence (Barbour and Restrepo, 2000;Kyes et al 2007). In this sense, genomics is fast expanding the list of common proteins among organisms (Pizza et al 2000;Kanduc et al 2008;Real et al 2013), and has proven to be useful in selecting common antigens for vaccine development against diseases, such as brucellosis (Cherwonogrodzky et al 2014), salmonellosis (Heithoff et al 2015) and encephalitis (Lobigs and Diamond, 2012). Since multiple Leishmania spp.…”