Conjugate Vaccines
Streptococcus pneumoniae Vaccine
Vaccines against Streptococcus pneumoniae
from James C. Paton writing in Vaccine Design: Innovative Approaches and Novel Strategies
Existing vaccines against Streptococcus pneumoniae are targeted at the capsular polysaccharide (PS) of which there are 91 distinct serotypes. Polyvalent purified PS vaccines are immunogenic in healthy adults, but not in high risk groups such as young children and the elderly. Development of PS-protein conjugate vaccines has overcome the poor immunogenicity of PS in children, but the protection imparted is strictly serotype-specific, and the number of included serotypes is even more restricted than in the PS vaccine formulations. Widespread introduction of conjugate vaccines in developed countries has dramatically reduced the incidence of invasive pneumococcal disease due to serotypes included in the vaccine. However, these benefits are being eroded by increases in the incidence of disease caused by non-vaccine serotypes. Conjugate vaccines are also expensive, limiting their use in developing countries, where the burden of pneumococcal disease is greatest. Clearly, there is an urgent need to develop alternative pneumococcal vaccines that are (i) inexpensive, (ii) immunogenic in young children, and (iii) provide protection against all pneumococci regardless of serotype. Of particular importance are vaccines comprising pneumococcal proteins that contribute to virulence and are common to all serotypes.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies | Bacterial Polysaccharides: Current Innovations and Future Trends
from James C. Paton writing in Vaccine Design: Innovative Approaches and Novel Strategies
Existing vaccines against Streptococcus pneumoniae are targeted at the capsular polysaccharide (PS) of which there are 91 distinct serotypes. Polyvalent purified PS vaccines are immunogenic in healthy adults, but not in high risk groups such as young children and the elderly. Development of PS-protein conjugate vaccines has overcome the poor immunogenicity of PS in children, but the protection imparted is strictly serotype-specific, and the number of included serotypes is even more restricted than in the PS vaccine formulations. Widespread introduction of conjugate vaccines in developed countries has dramatically reduced the incidence of invasive pneumococcal disease due to serotypes included in the vaccine. However, these benefits are being eroded by increases in the incidence of disease caused by non-vaccine serotypes. Conjugate vaccines are also expensive, limiting their use in developing countries, where the burden of pneumococcal disease is greatest. Clearly, there is an urgent need to develop alternative pneumococcal vaccines that are (i) inexpensive, (ii) immunogenic in young children, and (iii) provide protection against all pneumococci regardless of serotype. Of particular importance are vaccines comprising pneumococcal proteins that contribute to virulence and are common to all serotypes.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies | Bacterial Polysaccharides: Current Innovations and Future Trends
Glycoconjugate Vaccines
New Frontiers in the Chemistry of Glycoconjugate Vaccines
from David R. Bundle writing in Vaccine Design: Innovative Approaches and Novel Strategies
Methods for single point attachment of polysaccharides and oligosaccharides to protein carriers and T-cell peptides are important in vaccine design. Contemporary approaches involve synthetic oligosaccharides with linker or tether chemistry designed for compatibility with synthetic strategies. Current research involves the synthesis and evaluation of conjugate vaccines designed to combat infectious bacterial and fungal diseases, as well as the design and testing of therapeutic cancer vaccine. The prevailing dogma that protective B-cell epitopes should be comprised of 10-20 monosaccharides is confirmed for several experimental vaccines including those directed toward Shigell flexneri and Shigella dysenteriae. However, several small epitopes composed of 3-5 monosaccharide residues are sufficient to induce antibody against the whole organism and to confer protection.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies
from David R. Bundle writing in Vaccine Design: Innovative Approaches and Novel Strategies
Methods for single point attachment of polysaccharides and oligosaccharides to protein carriers and T-cell peptides are important in vaccine design. Contemporary approaches involve synthetic oligosaccharides with linker or tether chemistry designed for compatibility with synthetic strategies. Current research involves the synthesis and evaluation of conjugate vaccines designed to combat infectious bacterial and fungal diseases, as well as the design and testing of therapeutic cancer vaccine. The prevailing dogma that protective B-cell epitopes should be comprised of 10-20 monosaccharides is confirmed for several experimental vaccines including those directed toward Shigell flexneri and Shigella dysenteriae. However, several small epitopes composed of 3-5 monosaccharide residues are sufficient to induce antibody against the whole organism and to confer protection.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies