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Dr Doumagoum Moto Dagula's presentation at Meningitis Research Foundation's 2013 conference Meningitis & Septicaemia in Adults
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IMPACT OF SEROGROUP A MENINGOCOCCAL CONJUGATE VACCINE (MENAFRIVAC) ON
MENINGOCOCCAL MENINGITIS AND CARRIAGE IN CHAD
Caroline Trotter
University of Cambridge
GREETINGS FROM CHAD
Dr Daugla,Director
Dr Gamougam, Microbiologist
Centre de Support en Santé Internationale (CSSI)
Cases of meningitis
Year
Whole cell vaccines
Sulphonamides
Polysaccharide vaccines
Conjugate vaccine
MENINGITIS IN CHAD 1930-2011
THE AIMS OF MENAFRICAR
• To define the pattern of meningococcal carriage across the African meningitis belt and rates of acquisition and loss of carriage.
• To measure the impact of a new group A meningococcal conjugate vaccine (MenAfriVac) on carriage and disease.
MENAFRICAR CENTRES
Armauer Hansen Research Institute (AHRI), Ethiopia
Centre de Recherche Médicale et Sanitaire (CERMES), Niger
Centre de Support en Santé Internationale (CSSI), Chad
Centre pour le Développement des Vaccins (CVD-Mali), Mali
University of Maiduguri, Nigeria
The Navrongo Health Research Centre, Ghana
Institut de Recherche pour le Développement, Senegal
MENAFRICAR SURVEYS IN 2010
• First cross sectional studies performed July-December 2010
in seven countries.
• Group A meningococci identified only in carriers in Chad.
• Vaccine evaluation activities originally planned for Mali and
Niger moved to Chad.
CARRIAGE STUDIES IN CHAD
• MenAfriCar standard protocols• Rural area of Mandelia• First survey
• September-November 2010, N= 998
• Pre-vaccination survey• August- October 2011, N=4278
• Post-vaccination survey• April-June 2012, N=5001
Mandelia district - address by the Chef
Mandelia carriage survey - collecting a swab
Microbiology laboratory National hospital, N’Djamena
THE MENINGITIS VACCINE PROJECT
Aim
Production of an affordable,
serogroup A
meningococcal conjugate
vaccine for use in Africa
Established in 2001 with support fromthe Bill and Melinda Gates Foundation
WHO + PATH
MVP – ACHIEVEMENTS
• Efficient conjugation method developed and transferred
successfully to an Indian manufacturer.
• Phase 2 trials showed the vaccine to be safe and highly
immunogenic in children (Gambia and Mali) and young adults
(Mali, Senegal, Gambia).
• Vaccine safe and immunogenic in infants (Ghana).
• Vaccine licensed in India in 2009 and prequalified by WHO in 2010.
• Mass campaigns commenced in Burkina Faso, Mali and Niger
in those aged 1 – 29 years at the end of 2010.
< 10 YEARS FROM VACCINE DEVELOPMENT TO DEPLOYMENT
VACCINE MANUFACTURE
Serum Institute, Pune, India
MenAfriVac
MENAFRIVAC IMMUNISATION IN CHAD
• 1.8 million 1-29 year olds immunised in a planned vaccination campaign in 3 regions in and around N’Djamena over 10 days in December 2011.
• Reactive vaccination campaigns February - May 2012 - 9 districts exceeding the epidemic threshold- 3 other adjacent districts.
Districts in epidemic/ alert in 2012Districts vaccinated with “MenAfriVac” in December 2011
N’Djaména
VACCINATED DISTRICTS IN CHAD 2012
Mandelia
Moissala
MENINGITIS SURVEILLANCE
• Clinically diagnosed meningitis cases and deaths reported to district medical officer Ministry of Health WHO.
• CSF samples N’Djamena.
• Enhanced surveillance in 2012 in 3 vaccinated regions (MenAfriCar).
• Surveillance also enhanced in Moissala district, where reactive vaccination was undertaken in 2012 (MSF).
IMPACT OF MENAFRIVAC ON THE EPIDEMIc
[Adjusted incidence rate ratio =0.096 (95% CI 0.046, 0.198)]
94% difference in vaccinated compared to the unvaccinated areas
0
10
20
30
40
50
60
50 51 52 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
2011 2012
Semaine épidémiologique
No
mb
re d
e ca
s
Cas confirmés
Cas probables
campagne de vaccination
Confirmed cases
Probable cases
Vaccination campaign
Cases of meningitis by week of admission Moissala district, Chad, 2012 (n = 334)
(a)all probable and confirmed cases
(b)cases by serogroup (N=78). *
Vaccination campaign
0
5
10
15
50 51 52 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
2011 2012
Semaine epidémiologique
No
mb
re d
e ca
s
Non isolé
W135
A
campagne de vaccination
No serogroup identified
W
A
Vaccination campaign
a
b
REACTIVE VACCINATION IN MOISSALA DISTRICT
All meningococci
Epidemic strain
VACCINATION
Pre-vaccination Post-vaccination
Percentage carriage
(Daugla et al. Lancet 2013; electronic publication)
CARRIAGE RESULTS (1)
CARRIAGE RESULTS (2)
• 32/4278 group A carriers* in 2011 pre-vaccine survey.
• Only 1/5001 group A carrier post-vaccination.
• 98% difference in group A carriage prevalence.
• Adjusted Odds Ratio 0.019, 95% CI 0.002, 0.14.* serogroup A capsule region, rplF allele 1 (rplF-1), and a porA gene encoding the subtype P1.20,9
CARRIAGE RESULTS (3)
CONCLUSIONS
• MenAfriVac was highly effective at preventing serogroup A invasive meningococcal disease and carriage in Chad
during an epidemic.
• Together with previous studies from Burkina Faso, this study provides strong evidence of vaccine impact.
• Further work is required to evaluate the duration of protection and the influence of vaccination on other serogroups.
ACKNOWLEDGEMENTS Centre de Support en Santé International (CSSI), N’Djamena, Chad: DM Daugla, JP Gami, K Gamougam, N Naibei, L Mbainadji, M Narbé, J Toralta, B Kodbesse
Ministere de la Santé Publique, N’Djamena, Chad: C Ngadoua
Epicentre, Médecins sans Frontières, Paris, France: ME Coldiron, F Fermon U, A-L Page
WHO Intercountry Support Team, Ougadougou, Burkina Faso: MH Djingarey
Department of Pandemic and Epidemic Diseases, WHO, Geneva, Switzerland: S Hugonnet
Department of Zoology, University of Oxford, Oxford, UK: OB Harrison, LS Rebbetts, Y Tekletsion, ER Watkins, D Hill, MCJ Maiden
Norwegian Institute for Public Health, Oslo, Norway: D Caugant
Department of Veterinary Medicine, University of Cambridge, Cambridge, UK: C Trotter
Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK: D Chandramohan, M Hassan-King, O Manigart, M Nascimento, A Woukeu, JM Stuart, BM Greenwood
MenAfriCar is funded by The Bill & Melinda Gates Foundation & The Wellcome Trust