Patrick T Wedlock1, Elizabeth A Mitgang1, Leila A Haidari2, Wendy Prosser3, Shawn T Brown4, Kirstin Krudwig3, Sheryl S Siegmund1, Jay V DePasse2, Jennifer Bakal2, Jim Leonard2, Joel Welling2, Robert Steinglass3, Frances Dien Mwansa5, Guissimon Phiri5, Bruce Y Lee6. 1. HERMES Logistics Modeling Team, Baltimore, MD and Pittsburgh, PA, USA; HERMES Logistics Modeling Team, Pittsburgh, PA, USA; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA. 2. HERMES Logistics Modeling Team, Baltimore, MD and Pittsburgh, PA, USA; HERMES Logistics Modeling Team, Pittsburgh, PA, USA; Pittsburgh Supercomputing Center (PSC) at Carnegie Mellon University, 300 Craig Street, Pittsburgh, PA 15213, USA. 3. JSI Research & Training Institute, Inc. (JSI), USA. 4. HERMES Logistics Modeling Team, Baltimore, MD and Pittsburgh, PA, USA; HERMES Logistics Modeling Team, Pittsburgh, PA, USA; McGill Centre for Integrative Neuroscience, McGill Neurological Institute, McGill University, Montreal, Canada. 5. Ministry of Health, Zambia. 6. HERMES Logistics Modeling Team, Baltimore, MD and Pittsburgh, PA, USA; HERMES Logistics Modeling Team, Pittsburgh, PA, USA; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA. Electronic address: brucelee@jhu.edu.
Abstract
BACKGROUND: Frequently, a country will procure a single vaccine vial size, but the question remains whether tailoring the use of different size vaccine vial presentations based on populations or location characteristics within a single country could provide additional benefits, such as reducing open vial wastage (OVW) or reducing missed vaccination opportunities. METHODS: Using the Highly Extensible Resource for Modeling Supply Chains (HERMES) software, we built a simulation model of the Zambia routine vaccine supply chain. At baseline, we distributed 10-dose Measles-Rubella (MR) vials to all locations, and then distributed 5-dose and 1-dose MR vials to (1) all locations, (2) rural districts, (3) rural health facilities, (4) outreach sites, and (5) locations with average MR session sizes <5 and <10 children. We ran sensitivity on each scenario using MR vial opening thresholds of 0% and 50%, i.e. a healthcare worker opens an MR vaccine for any number of children (0%) or if at least half will be used (50%). RESULTS: Replacing 10-dose MR with 5-dose MR vials everywhere led to the largest reduction in MR OVW, saving 573,892 doses (103,161 doses with the 50% vial opening threshold) and improving MR availability by 1% (9%). This scenario, however, increased cold chain utilization and led to a 1% decrease in availability of other vaccines. Tailoring 5-dose MR vials to rural health facilities or based on average session size reduced cold transport constraints, increased total vaccine availability (+1%) and reduced total cost per dose administered (-$0.01) compared to baseline. CONCLUSIONS: In Zambia, tailoring 5-dose MR vials to rural health facilities or by average session size results in the highest total vaccine availability compared to all other scenarios (regardless of OVT policy) by reducing open vial wastage without increasing cold chain utilization.
BACKGROUND: Frequently, a country will procure a single vaccine vial size, but the question remains whether tailoring the use of different size vaccine vial presentations based on populations or location characteristics within a single country could provide additional benefits, such as reducing open vial wastage (OVW) or reducing missed vaccination opportunities. METHODS: Using the Highly Extensible Resource for Modeling Supply Chains (HERMES) software, we built a simulation model of the Zambia routine vaccine supply chain. At baseline, we distributed 10-dose Measles-Rubella (MR) vials to all locations, and then distributed 5-dose and 1-dose MR vials to (1) all locations, (2) rural districts, (3) rural health facilities, (4) outreach sites, and (5) locations with average MR session sizes <5 and <10 children. We ran sensitivity on each scenario using MR vial opening thresholds of 0% and 50%, i.e. a healthcare worker opens an MR vaccine for any number of children (0%) or if at least half will be used (50%). RESULTS: Replacing 10-dose MR with 5-dose MR vials everywhere led to the largest reduction in MR OVW, saving 573,892 doses (103,161 doses with the 50% vial opening threshold) and improving MR availability by 1% (9%). This scenario, however, increased cold chain utilization and led to a 1% decrease in availability of other vaccines. Tailoring 5-dose MR vials to rural health facilities or based on average session size reduced cold transport constraints, increased total vaccine availability (+1%) and reduced total cost per dose administered (-$0.01) compared to baseline. CONCLUSIONS: In Zambia, tailoring 5-dose MR vials to rural health facilities or by average session size results in the highest total vaccine availability compared to all other scenarios (regardless of OVT policy) by reducing open vial wastage without increasing cold chain utilization.
Authors: Sarah N Cox; Patrick T Wedlock; Sarah W Pallas; Elizabeth A Mitgang; Tatenda T Yemeke; Sarah M Bartsch; Taiwo Abimbola; Sheryl S Sigemund; Aaron Wallace; Sachiko Ozawa; Bruce Y Lee Journal: Vaccine Date: 2021-05-25 Impact factor: 3.641
Authors: Bruce Y Lee; Patrick T Wedlock; Elizabeth A Mitgang; Sarah N Cox; Leila A Haidari; Manoja K Das; Srihari Dutta; Bhrigu Kapuria; Shawn T Brown Journal: BMJ Glob Health Date: 2019-09-05
Authors: Patrick T Wedlock; Sarah N Cox; Sarah M Bartsch; Samuel L Randall; Kelly J O'Shea; Marie C Ferguson; Sheryl S Siegmund; Bruce Y Lee Journal: Vaccine Date: 2021-06-19 Impact factor: 4.169
Authors: F T Cutts; E Dansereau; M J Ferrari; M Hanson; K A McCarthy; C J E Metcalf; S Takahashi; A J Tatem; N Thakkar; S Truelove; E Utazi; A Wesolowski; A K Winter Journal: Vaccine Date: 2019-11-29 Impact factor: 3.641