Serogroup A meningococcal conjugate vaccines in Africa

Kristiansen, Paul A.; Jørgensen, Hannah Joan; Caugant, Dominique A.

doi:10.1586/14760584.2015.1084232

Cited by 10 publications

(8 citation statements)

References 82 publications

(56 reference statements)

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“…Meningococcal serogroup A disease is at its lowest level in Sub-Saharan Africa than in recent decades, in large part because of widespread vaccination with a low cost serogroup A polysaccharide-protein conjugate vaccine [6, 15]. The remaining challenge is prevention of serogroup C, W or X disease [12–15, 34] (for unknown reasons, serogroup B disease is rare in the region [30]).…”

Section: Discussionmentioning

confidence: 99%

“…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%

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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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Section: Discussionmentioning

confidence: 99%

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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“…Meningococcal vaccines have successfully been used to control epidemics and prevent disease . Vaccines based on capsular polysaccharides from meningococcal serogroups A (MenA), C (MenC), W (MenW) and Y (MenY), four of the five major disease‐causing serogroups , have largely been replaced by conjugated vaccines, where the polysaccharides are coupled to carrier proteins.…”

Section: Introductionmentioning

confidence: 99%

Salivary and Serum Antibody Response Against Neisseria meningitidis After Vaccination With Conjugate Polysaccharide Vaccines in Ethiopian Volunteers

et al. 2016

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Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive disease. Salivary antibodies are believed to be important for hindering meningococcal acquisition and/or clearance of established carriage. In this study, we measured salivary IgA and IgG antibodies induced by vaccination with a monovalent serogroup A conjugate vaccine or a tetravalent A, C, W and Y conjugate vaccine, in comparison with antibody levels in serum. Saliva and serum samples from Ethiopian volunteers (1-29 years) collected before and eight times on a weekly basis after receiving the serogroup A conjugate vaccine, the tetravalent serogroup A, C, W and Y conjugate vaccine, or no vaccine (control group), were analysed using a multiplex microsphere immunoassay for antibody detection. Serogroup-specific IgG antibody levels in saliva increased significantly after vaccination with both vaccines. The monovalent serogroup A vaccine also induced an increase in salivary IgA antibodies. A strong correlation between serogroup-specific IgG antibodies in saliva and serum, and a somewhat lower correlation for IgA, was observed for all serogroups. There was also a strong correlation between specific secretory IgA and IgA antibodies in saliva for all serogroups. Meningococcal conjugate vaccines are able to elicit salivary antibodies against serogroup A, C, W and Y correlating with antibody levels in serum. The strong correlation between saliva and serum antibody levels indicates that saliva may be used as a surrogate of systemic antibody responses.

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“…La couverture estimée allait de 90,8% à 98,3% dans les différentes régions ; la couverture estimée était de 97,0% chez les enfants de 2 à 5 ans ; de 97,4% pour les enfants de 6 à 15 ans et de 93,4% pour les personnes de 16 à 30 ans[14]. Tous ces résultats confirment l'engouement des populations des pays de la ceinture méningitique pour la lutte contre les épidémies meurtrières de méningite à méningocoque A. L'introduction de ce vaccin MenAfriVac en Afrique Sub-saharienne, a contribué ainsi à modifier très significativement le profil épidémiologique de ces épidémies [15, 16]. Ceci devraient ouvrir la voie à la mise au point d'autres vaccins conjugués contre d'autres sérotypes de méningocoque, mais aussi d'autres germes responsables de grandes épidémies en Afrique subsaharienne comme le pneumocoque et Haemophilus influenzae .…”

Section: Discussionunclassified

L’utilisation de l’approche CTC: quel impact sur la couverture vaccinale lors de la campagne préventive de vaccination contre la méningite A avec le MenAfriVac au Togo en 2014 ?

Landoh¹,

Kahn

Lacle

et al. 2017

Pan Afr Med J

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IntroductionUne campagne de vaccination contre la méningite A avec le vaccin MenAfriVac a été organisée dans les quatre régions septentrionales du Togo du 28 novembre au 07 décembre 2014. L'approche CTC a été utilisée pour la première fois à une grande échelle pour la campagne de vaccination dans dix districts sanitaires du Togo. L'objectif de cette étude était d'estimer la couverture vaccinale et, de déterminer l'effet de l'utilisation de la Chaîne à Température Contrôlée (CTC) sur ces couvertures vaccinales.MéthodesL'enquête s'est déroulée du 9 au 14 mars 2015, soit environ 3 mois après la fin de la campagne de vaccination dans ces quatre régions. Le sondage en grappe à deux degrés stratifiés selon les régions a été utilisé. Dans 10 districts, le Togo a fait le choix d'utiliser le vaccin MenAfriVac en CTC.RésultatsAu total, 2707 ménages ont été enquêtés et 9082 personnes âgées de 1 à 29 ans ont été interviewées. L'âge moyen des personnes enquêtées était de 11,8±7,7 ans et le sex-ratio (H/F) de 1,01. Le nombre moyen de personnes par ménage était de 5,7 et celui des personnes de 1 à 29 ans ciblées par la campagne était de 3,4. Sur les 9082 personnes enquêtées, 8889 (98%) étaient vaccinées. En analyse multivariée, les facteurs associés à la couverture vaccinale avec le MenAfrivac étaient la résidence dans la zone au moment de la campagne (aOR = 4,52 ; 95%IC = [4.07 - 4.97]) et le fait d'être informé de la campagne avant son démarrage (aOR=2,42 ; 95%IC = [2.05 - 2.80]). Par contre, la couverture vaccinale n'était pas différente selon la zone ayant utilisé l'approche CTC ou non (aOR=0,09 ; 95%IC = [-0,27-0,45]). Deux cent sept personnes interrogées (2,3%) ont déclaré avoir eu une Manifestation Adverse Post Immunisation (MAPI) après l'administration du vaccin. Il s'agissait surtout de MAPI mineures à type de fièvre, d'abcès et de gonflement au point d'injection.ConclusionLes résultats de cette enquête montrent que l'utilisation de la CTC dans un pays à ressources limitées comme le Togo n'a pas eu un effet négatif sur les couvertures vaccinales. En effet, il n'y avait pas de différence entre la couverture vaccinale dans les zones CTC et celles non CTC. Il importe de capitaliser l'expérience acquise pour l'utilisation des vaccins du Programme Elargi de Vaccination avec l'approche CTC surtout dans les pays à ressources limitées confrontés à la disponibilité de la chaîne de froid.BackgroundA vaccination campaign against meningitis A using MenAfriVac vaccine was implemented in the four regions of northern Togo from 28 November to 7 December 2014. CTC approach was first used on a large scale in a vaccination campaign in ten health districts in Togo. This study aims to estimate the immunization coverage and to determine the effect of Controlled Temperature Chain (CTC) approach on these immunization coverages.

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Serogroup A meningococcal conjugate vaccines in Africa

Cited by 10 publications

References 82 publications

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

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

Salivary and Serum Antibody Response Against Neisseria meningitidis After Vaccination With Conjugate Polysaccharide Vaccines in Ethiopian Volunteers

L’utilisation de l’approche CTC: quel impact sur la couverture vaccinale lors de la campagne préventive de vaccination contre la méningite A avec le MenAfriVac au Togo en 2014 ?

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