title: Public Health Impact After the Introduction of PsA-TT: The First 4 Years.
abstract: BACKGROUND
  During the first introduction of a group A meningococcal vaccine (PsA-TT) in 2010-2011 and its rollout from 2011 to 2013, >150 million eligible people, representing 12 hyperendemic meningitis countries, have been vaccinated.
  
  
  METHODS
  The new vaccine effectiveness evaluation framework was established by the World Health Organization and partners. Meningitis case-based surveillance was strengthened in PsA-TT first-introducer countries, and several evaluation studies were conducted to estimate the vaccination coverage and to measure the impact of vaccine introduction on meningococcal carriage and disease incidence.
  
  
  RESULTS
  PsA-TT implementation achieved high vaccination coverage, and results from studies conducted showed significant decrease of disease incidence as well as significant reduction of oropharyngeal carriage of group A meningococci in vaccinated and unvaccinated individuals, demonstrating the vaccine's ability to generate herd protection and prevent group A epidemics.
  
  
  CONCLUSIONS
  Lessons learned from this experience provide useful insights in how to guide and better prepare for future new vaccine introductions in resource-limited settings.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Fabien V K
authors.initials: FV
authors.lastname: Diomandé
authors.affiliation: Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso.
authors.forename: Mamoudou H
authors.initials: MH
authors.lastname: Djingarey
authors.affiliation: Centre de Support en Santé International, N'Djamena, Chad.
authors.forename: Doumagoum M
authors.initials: DM
authors.lastname: Daugla
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Novak
authors.affiliation: World Health Organization, Collaborating Center for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kristiansen
authors.affiliation: Centre de Recherche Médicale et Sanitaire, Niamey, Niger.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Collard
authors.affiliation: Centre de Support en Santé International, N'Djamena, Chad.
authors.forename: Kadidja
authors.initials: K
authors.lastname: Gamougam
authors.affiliation: Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso.
authors.forename: Denis
authors.initials: D
authors.lastname: Kandolo
authors.affiliation: Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso.
authors.forename: Nehemie
authors.initials: N
authors.lastname: Mbakuliyemo
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Leonard
authors.initials: L
authors.lastname: Mayer
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Stuart
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Clark
authors.affiliation: World Health Organization, Regional Office for Africa, Brazzaville, Republic of Congo.
authors.forename: Carol
authors.initials: C
authors.lastname: Tevi-Benissan
authors.affiliation: Department of Pandemic and Epidemic Diseases, World Health Organization, Geneva, Switzerland.
authors.forename: William A
authors.initials: WA
authors.lastname: Perea
authors.affiliation: Meningitis Vaccine Project, PATH, Ferney-Voltaire, France Meningitis Vaccine Project, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Preziosi
authors.affiliation: Serum Institute of India, Ltd, Pune.
authors.forename: F
authors.initials: F
authors.lastname: Marc LaForce
authors.affiliation: Centre de Recherche Médicale et Sanitaire, Niamey, Niger.
authors.forename: Dominique
authors.initials: D
authors.lastname: Caugant
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Nancy
authors.initials: N
authors.lastname: Messonnier
authors.affiliation: Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso.
authors.forename: Oladapo
authors.initials: O
authors.lastname: Walker
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom.
authors.forename: Brian
authors.initials: B
authors.lastname: Greenwood
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology* / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C573970:MenAfriVac; D022401:Meningococcal Vaccines
keywords: Africa meningitis belt; PsA-TT; disease incidence; meningococcal group A; vaccine evaluation framework