Emergence of serogroup X meningococcal disease in Africa: Need for a vaccine

Development of a glycoconjugate vaccine to prevent meningitis in Africa caused by meningococcal serogroup X

“…Despite the widespread implementation of a MenA-tetanus toxoid conjugate vaccine in the African meningitis belt and the availability of PS and conjugate MenW vaccines, this area is vulnerable to increased incidence of meningitis caused by MenX for which no vaccine is available (45). Because the development of a new vaccine through to licensure takes many years, this leaves Africa vulnerable to new epidemics of MenX meningitis at a time when the epidemiology of meningococcal meningitis on the continent is changing rapidly (13).…”

“…MenX has recently emerged as a cause of meningitis outbreaks with epidemic potential in sub-Saharan Africa, where MenA and MenW have previously been the dominant causes of meningococcal disease (2,45). Although it is uncertain how MenX will contribute to the problem of meningitis in Africa in the future, preparedness would be prudent in the face of changing epidemiology surrounding the introduction of the serogroup A conjugate vaccine.…”

The Capsule Polymerase CslB of Neisseria meningitidis Serogroup L Catalyzes the Synthesis of a Complex Trimeric Repeating Unit Comprising Glycosidic and Phosphodiester Linkages

“…One of the mechanisms underlying serogroup replacement is called capsule switching, a genetic event in which the genes necessary for capsule biosynthesis are exchanged between serogroups (21,26,27). Nevertheless, the sporadic occurrence of invasive meningococcal disease due to serogroups with currently low pathogenic potential (28,29) demonstrates that eradication of invasive meningococcal disease will profit from vaccines against rare serogroups.…”

Meningococcal quadrivalent tetanus toxoid conjugate vaccine (MenACWY-TT, Nimenrix™): A review of its immunogenicity, safety, co-administration, and antibody persistence

“…28 Not until recently has serogroup X emerged as a cause of a number of outbreaks in the meningitis belt threatening with its epidemic potential especially following the introduction of the MenA conjugate vaccine. 26,29 Thus, the development of a vaccine against serogroup X has only recently become a public health need and will likely be included in future combination vaccines as serogroup X spreads. Currently there are three types of vaccines; the PS and PS-protein conjugated vaccines for serogroups A, C, W, and Y and vaccines based on the bacterium outer membrane proteins 15,30 developed for the control of serogroup B disease.…”