Persistent low carriage of serogroup A Neisseria meningitidistwo years after mass vaccination with the meningococcal conjugate vaccine, MenAfriVac

Kristiansen, Paul A.; Ba, Absatou Ky; Ouédraogo, Abdoul–Salam; Sanou, Idrissa; Ouédraogo, Rasmata; Sangaré, Lassana; Diomandé, Fabien; Kandolo, Denis; Saga, Inger Marie; Misegades, Lara; Clark, Thomas A.; Préziosi, Marie-Pierre; Caugant, Dominique A.

doi:10.1186/s12879-014-0663-4

Cited by 57 publications

(64 citation statements)

References 45 publications

(78 reference statements)

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“…The surveys conducted in the same sites a year after MenAfriVac R vaccination identified mostly NmX belonging to ST‐181 (5.33% of the samples) . Two years after MenAfriVac R vaccination, Nm W from ST‐11 cc dominated with a carriage prevalence of 6.85% .…”

Section: Resultsmentioning

confidence: 99%

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Narrative review of methods and findings of recent studies on the carriage of meningococci and other Neisseria species in the African Meningitis Belt

Greenwood

Aseffa

Caugant

et al. 2018

Tropical Med Int Health

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Objective To review the findings of studies of pharyngeal carriage of Neisseria meningitidis and related species conducted in the African meningitis belt since a previous review published in 2007. Methods PubMed and Web of Science were searched in July 2018 using the terms ‘meningococcal OR Neisseria meningitidis OR lactamica AND carriage AND Africa’, with the search limited to papers published on or after 1st January 2007. We conducted a narrative review of these publications. Results One hundred and thirteen papers were identified using the search terms described above, 20 of which reported new data from surveys conducted in an African meningitis belt country. These papers described 40 surveys conducted before the introduction of the group A meningococcal conjugate vaccine (MenAfriVacR) during which 66 707 pharyngeal swabs were obtained. Carriage prevalence of N. meningitidis varied substantially by time and place, ranging from <1% to 24%. The mean pharyngeal carriage prevalence of N. meningitidis across all surveys was 4.5% [95% CI: 3.4%, 6.8%] and that of capsulated N. meningitidis was 2.8% [95% CI: 1.9%; 5.2%]. A study of households provided strong evidence for meningococcal transmission within and outside households. The introduction of MenAfriVac® led to marked reductions in carriage of the serogroup A meningococcus in Burkina Faso and Chad. Conclusions Recent studies employing standardised methods confirm the findings of older studies that carriage of N. meningitidis in the African meningitis belt is highly variable over time and place, but generally occurs with a lower prevalence and shorter duration than reported from industrialised countries.

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Section: Resultsmentioning

confidence: 99%

“…The impact of group A meningococcal conjugate vaccine MenAfriVac R on pharyngeal carriage of the group A meningococcus in (a) Burkina Faso and (b) Chad . Figure a is modified from reference with permission.…”

Section: Resultsmentioning

confidence: 99%

Narrative review of methods and findings of recent studies on the carriage of meningococci and other Neisseria species in the African Meningitis Belt

Greenwood

Aseffa

Caugant

et al. 2018

Tropical Med Int Health

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“…In 2010, a low cost serogroup A polysaccharide-protein conjugate vaccine (MenAfriVac) was introduced [2–4]. The vaccine conferred protection against invasive disease [5, 6] as well as asymptomatic nasopharyngeal carriage of serogroup A strains [7–9], but failed to curtail disease or carriage by strains with serogroups C, X, or W, which also cause epidemics in the region [10–15]. Meningococcal A,C,Y and W conjugate vaccines, which are available in industrialized countries, can prevent epidemics caused by these strains.…”

Section: Introductionmentioning

confidence: 99%

A meningococcal NOMV-FHbp vaccine for Africa elicits broader serum bactericidal antibody responses against serogroup B and non-B strains than a licensed serogroup B vaccine

Pajón

Lujan

Granoff

2016

Vaccine

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Background Meningococcal epidemics in Sub-Sahara caused by serogroup A strains are controlled by a group A polysaccharide conjugate vaccine. Strains with serogroups C, W and X continue to cause epidemics. Protein antigens in licensed serogroup B vaccines are shared among serogroup B and non-B strains. Purpose Compare serum bactericidal antibody responses elicited by an investigational native outer membrane vesicle vaccine with over-expressed Factor H binding protein (NOMV-FHbp) and a licensed serogroup B vaccine (MenB-4C) against African serogroup A, B, C, W and X strains. Methods Human Factor H (FH) transgenic mice were immunized with NOMV-FHbp prepared from a mutant African meningococcal strain containing genetically attenuated endotoxin and a mutant sub-family B FHbp antigen with low FH binding, or with MenB-4C, which contains a recombinant sub-family B FHbp antigen that binds human FH, and three other antigens, NHba, NadA and PorA P1.4, capable of eliciting bactericidal antibody. Results The NOMV-FHbp elicited serum bactericidal activity against 12 of 13 serogroup A, B, W or X strains from Africa, and four isogenic serogroup B mutants with subfamily B FHbp sequence variants. There was no activity against a serogroup B mutant with sub-family A FHbp, or two serogroup C isolates from a recent outbreak in Northern Nigeria, which were mismatched for both PorA and sub-family of the FHbp vaccine antigen. For MenB-4C, NHba was expressed by all 16 African isolates tested, FHbp sub-family B in 13, and NadA in five. However, MenB-4C elicited titers ≥1:10 against only one isolate, and against only two of four serogroup B mutant strains with sub-family B FHbp sequence variants. Conclusions NOMV-FHbp has greater potential to confer serogroup-independent protection in Africa than the licensed MenB-4C vaccine. However, the NOMV-FHbp vaccine will require inclusion of sub-family A FHbp for coverage against recent serogroup C strains causing outbreaks in Northern Nigeria.

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“…16,17 In addition to persistent low carriage of meningococcal serogroup A, other serogroups like Y and X are causing meningococcal infections in sub-Saharan Africa. 7,[18][19][20] Therefore, designing novel meningococcal vaccine nanoparticles formulations that cover emerging and persistent meningococcal disease-causing serogroups with enhanced antigenicity have advantages over currently used conjugate vaccines. The novel nanotechnology-based formulations will provide suitable solution not just to low resource countries with endemic and heavy disease burden but also suitable for vaccinations required for the annual Hajj season.…”

Section: The Potential For Novel Meningococcal Vaccine Formulationsmentioning

confidence: 99%

Analysis of novel meningococcal vaccine formulations

Zughaier

2017

Human Vaccines & Immunotherapeutics

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The protective effect of meningococcal vaccines targeting disease causing serogroups exemplified by the introduction of MenAfriVac TM in Africa, is well established and documented in large population-based studies. Due to the emergence of other meningococcal disease causing serogroups, novel vaccine formulations are needed. There is a high potential for novel nanotechnology-based meningococcal vaccine formulations that can provide wider vaccine coverage. The proposed meningococcal vaccine formulation contains spherical shaped micro and nanoparticles that are biological mimics of Niesseria meningitidis, therefore present to immune system as invader and elicit robust immune responses. Vaccine nanoparticles encapsulate meningococcal CPS polymers in a biodegradable material that slowly release antigens, therefore enhance antigen presentation by exerting antigen depot effect. The antigenicity of meningococcal vaccine delivered in nanoparticles is significantly higher when compared to vaccine delivered in solution. Preclinical studies are required to assess the immunogenicity of novel vaccine formulations. Therefore, implementing various in-vitro human immune cell-based assays that mimic invivo interactions, would provide good insight on optimal antigen dose, effective antigen presentation, facilitate screening of various vaccine and adjuvant combinations and predict in-vivo immunogenicity. This rapid approach is cost-effective and provides data required for the preclinical immunogenicity assessment of novel meningococcal vaccine formulations.

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Persistent low carriage of serogroup A Neisseria meningitidistwo years after mass vaccination with the meningococcal conjugate vaccine, MenAfriVac

Cited by 57 publications

References 45 publications

Narrative review of methods and findings of recent studies on the carriage of meningococci and other Neisseria species in the African Meningitis Belt

Narrative review of methods and findings of recent studies on the carriage of meningococci and other Neisseria species in the African Meningitis Belt

A meningococcal NOMV-FHbp vaccine for Africa elicits broader serum bactericidal antibody responses against serogroup B and non-B strains than a licensed serogroup B vaccine

Analysis of novel meningococcal vaccine formulations

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