Neisseria meningitidis Vaccines
Meningitis is a disease that seriously affects people's health. Neisseria meningitidis is one of its pathogens. The most effective strategy for this disease is vaccine. Creative Biolabs is a professional vaccine research company. The company has in-depth and extensive research on Neisseria meningitidis. We have a wealth of products and services related to N. meningitidis vaccine, which can help customers successfully complete the research and development of N. meningitidis vaccine.
Neisseria meningitidis
Neisseria meningitidis, also known as meningococcus, is a gram-negative diplococcus that causes meningitis and meningococcemia. The bacterium is a diplococcus, which is mainly found in the nasopharynx of the human body, and approximately 10% of adults are carriers of the bacterium. Neisseria meningitidis is a human-specific pathogen and a major cause of bacterial encephalitis in young people and children. Developmental disorders and death caused by the bacterium occur in approximately 10% of cases. N. meningitidis is generally spread through saliva and respiratory secretions, so infected people can spread the pathogen when they sneeze, cough, kiss, and share water with others. N. meningitidis can only obtain iron resources from lactoferrin and transferrin in humans, so humans are the only host. The bacterium is also part of the normal nasopharyngeal flora of some adults. According to the antigenic structure of the polysaccharide capsule of Neisseria meningitidis, the pathogen can be divided into different pathogenic strains.
Pathogenicity of Neisseria meningitidis
Among the 13 different capsule types of Neisseria meningitidis that have been identified, the six types A, B, C, X, Y, and W135 are the main pathogenic strains of the bacterium. Type A is the main epidemic strain in Africa and Asia, and type B and type C are the major pathogenic strains in the United States. The diversity of meningococcal subtypes also makes it difficult to develop a universal vaccine against the bacteria. The pathogenicity of N. meningitidis is related to a variety of factors. Among them, the bacterial outer membrane component Lipooligosaccharide (LOS) as a bacterial exotoxin can cause red blood cell destruction and cause bleeding and even septic shock. The polysaccharide capsule can block the host's phagocytosis of bacteria and help N. meningitidis escape the body's immune response. Fimbriae mediate bacterial attachment to epithelial cells in the nasopharynx through its surface pili and Opa and Opc proteins. N. meningitidis is also capable of producing a protease that breaks down IgA, thus evading a part of the host's humoral immune response. The Factor H binding protein (fHbp) protein of N. meningitidis is the major inhibitor of the alternative complement pathway. fHbp not only protects N. meningitidis from death mediated by complement in serum. And in vitro tests have shown that it also protects bacteria against antimicrobial peptides. The important role of fHbp in the pathogenicity of N. meningitidis makes it a major target for the N. meningitidis vaccine.
Fig.1 Schematic illustration of Neisseria meningitidis outer membrane proteins interacting with complement components. (Pizza M and Rappuoli R, 2015)
Development of the Neisseria meningitidis Vaccines
The world's first available Neisseria meningitidis vaccine was produced in 1979s. The vaccine has been included in the list of essential medicines by WHO and is the safest and most effective meningococcal vaccine. Serogroups, A, B, C, Y, W-135, and X almost cover all cases of human N. meningitidis infection, so the N. meningitidis vaccine under study is basically directed at these six serotypes. Existing N. meningitidis vaccines under study include quadrivalent vaccines for serogroups A, C, W-135, and Y, bivalent vaccines for serogroups C and Y, and vaccines for serogroup A, B, and X, respectively.
The capsular polysaccharide is the major antigen of the A, C, W135, and Y serogroups, and is also the basis for designing a conjugate vaccine as well as has a preventive effect on meningitis of different ages. However, for the B serogroup, since the structure of the capsular polysaccharide is the same as that of human polysialic acid, it is weakly immunogenic and cannot be used as a target for vaccines. In response to this problem, vaccines prepared using bacterial OMVs (outer membrane vesicles) have shown good results. The diversity of meningococcal surface proteins is the bottleneck in the design of such bacterial vaccines. Creative Biolabs has advanced strategies and extensive experience to solve these challenges. On the one hand, we can screen bacterial protective antigens by reverse vaccinology to provide a basis for vaccine design. On the other hand, we use different variants of the same antigen to prepare a combination vaccine to achieve the broad protection of the vaccine. In addition, we have a strategy portfolio to meet the safety and effectiveness of vaccine development.
More than a decade of precipitation and research has made Creative Biolabs a world-renowned vaccine development expert. We have a team of advanced scientists from around the world, mature and comprehensive platforms and technologies and have provided high-quality and reliable products and services to countless researchers around the world. Whether you have any needs for vaccine development, please let us serve you.
Reference
- Pizza M, Rappuoli R. (2015). “Neisseria meningitidis: pathogenesis and immunity”. Curr Opin Microbiol. 23, 68-72.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
