title: Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model.
abstract: BACKGROUND
  Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks.
  
  
  METHODS
  We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes.
  
  
  RESULTS
  Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively.
  
  
  CONCLUSIONS
  The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.
authors.affiliation: University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Tina-Marie
authors.initials: TM
authors.lastname: Assi
authors.forename: Shawn T
authors.initials: ST
authors.lastname: Brown
authors.forename: Ali
authors.initials: A
authors.lastname: Djibo
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Norman
authors.forename: Jayant
authors.initials: J
authors.lastname: Rajgopal
authors.forename: Joel S
authors.initials: JS
authors.lastname: Welling
authors.forename: Sheng-I
authors.initials: SI
authors.lastname: Chen
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Bailey
authors.forename: Souleymane
authors.initials: S
authors.lastname: Kone
authors.forename: Hailu
authors.initials: H
authors.lastname: Kenea
authors.forename: Diana L
authors.initials: DL
authors.lastname: Connor
authors.forename: Angela R
authors.initials: AR
authors.lastname: Wateska
authors.forename: Anirban
authors.initials: A
authors.lastname: Jana
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Wisniewski
authors.forename: Willem G
authors.initials: WG
authors.lastname: Van Panhuis
authors.forename: Donald S
authors.initials: DS
authors.lastname: Burke
authors.forename: Bruce Y
authors.initials: BY
authors.lastname: Lee
mesh_terms: D004349:Drug Packaging / Q000592:standards*; D004356:Drug Storage / Q000379:methods*; D006801:Humans; D008458:Measles Vaccine / Q000191:economics / Q000600:supply & distribution*; D015233:Models, Statistical; D009548:Niger
chemical_list: D008458:Measles Vaccine