Vaccines bacterial vectors

Various bacterial vectors have been used to express a number of bacterial B. pertussis, S. pneumoniae, Y. pestis, and L. monocytogenes), viral (herpesvirus, influenza virus, human immunodeficiency virus, simian immunodeficiency virus, and hepatitis B virus), and parasitic (5. mansoni, and L. major) antigens. Significant improvements in attenuation of bacteria, and the stability, localization, and expression levels of heterologous antigens are required to market the bacterial vector-based vaccines for use in humans or animals. 

Vaccine production is pursued with the objectives to genetically engineer vaccines with specific gene deletions reducing virulence produce viral and bacterial vectored vaccines and develop subunit vaccines using purified antigens obtained from in vitro expression vectors such as pseudorabies purified protein vaccine and foot-and-mouth disease vaccine. 

Killeen, K., D. Spriggs, and J. Mekalanos, Bacterial mucosal vaccines Vibrio cholerae as a live attenuated vaccine/vector paradigm. Curr Top Microbiol Immunol, 1999. 236 237-54. 

A range of different vaccine vectors has been developed over time to provoke an immune response within the body [127,142], However, it has only been comparatively recently that they have been applied to inducing mucosal immunity within the uterovaginal tract. The general vector platforms that have been used include attenuated viruses, live viruses, commensal bacteria, DNA vectors, and protein subunit/peptide or virus-like particles (Table 21.9). The choice of vector is dependent on a number of factors such as the pathogenic virus and bacterial type and the length of duration of immunity required. 

Walsh (2003) defined biopharmaceuticals as therapeutic protein or nucleic acid preparations made by techniques involving recombinant deoxyribonucleic acid (DNA) technology. Therapeutic proteins include blood clotting factors and plasminogen activators, hemopoietic factors, hormones, interferons and interleukins, and monoclonal antibodies (LeVine, 2006). Over time, the term biopharmaceutical has broadened, and, in addition to proteins and nucleic acids, now includes bacteriophages, viral and bacterial vaccines, vectors for gene therapy, and cells for cell therapy (Primrose and Twyman, 2004). Attention here focuses on proteins, since the majority of approved biopharmaceuticals are proteins. 

Oggioni, M. R., Medaglini, D., Maggi, T., and Pozzi, G. (1999), Engineering the grampositive cell surface for construction of bacterial vaccine vectors, Methods, 19, 163-173. 

Vaccines may be considered as representing live microorganisms, killed microorganisms or purified bacterial and viral components (component vaccines). Recent innovations have included the introduction of DNA vaccines that encode for the transcription of antigen when introduced directly into host tissues or that might be delivered by virus vectors (i.e. adenovirus). Some aspects of these vaccine classes are discussed below. 

The other m or health care products produced with the help of bioprocess engineering are steroids, bacterial vaccines, gene therapy vectors, and therapeutic proteins such as interferon, growth hormone, and insulin. Steroids are important hormones that are manufactured by the process of biotransformation, in which microorganisms are used to chemically... 

The other major health care products produced with the help of industrial fermentation are bacterial vaccines, therapeutic proteins, steroids, and gene therapy vectors. There are two categories of bacterial vaccines living and inactivated vaccines. Living vaccines consist of weakened, also known as attenuated, bacteria. Examples of living vaccines include those for diseases such as anthrax, which is caused by Bacillus anthracis, and typhoid fever, which is caused by Salmonella typhi. Inactivated vaccines are composed... 

Vaccine adjuvants Plasmid vaccines that can successfully elicit humoral and cellular immune response have the potential to provide safer alternatives than live viral or heat-killed bacterial vaccines. Therapeutically relevant immune response is attainable with adjuvants such as cholera toxin and lipid A delivered using cationic nanoparticles by topical and subcutaneous administration, respectively [45]. Additionally, protein-based vaccines may be encapsulated in pH sensitive polymers, where low pH in the phagosomes of antigen-presenting cells disrupt the vectors to release vaccines [ 37]. 

---