Resilient and sustainable global COVID-19 vaccine supply chain design considering reverse logistics

Abstract

This study proposes a multi-mode, multi-product, and multi-objective optimization model to design a resilient and sustainable global COVID-19 vaccine supply chain network under operational risks. The network includes a forward chain for vaccine supply, production, and distribution and a reverse chain for vaccine waste management. The objective functions comprise minimizing the total network costs and environmental pollution caused by the waste of vaccination centers and the transportation between facilities, as well as considering social impacts (maximizing regional development and the effect of domestic vaccine production on self-sufficiency, and minimizing the impact of vaccine side-effects). Resilience strategies are employed to deal with the disruption risks in different facilities and transportation links of the chain, including multiple sources of raw material supply, vaccine production and distribution, and waste management facilities; import; multiple transportation modes and different vehicles in each mode; inventory holding; capacity expansion; transshipment; and fortification of facilities. Financial parameters, including exchange rate and international transport insurance for importing raw materials and vaccines, are also considered in the presented model. An actual-world case study in Iran is conducted to indicate the model's applicability. Finally, by analyzing the computational results, important research implications are presented. The analyses investigate the conflict of objectives, examine the impact of vaccine side-effects on production and import, assess the efficiency of resilience strategies in the face of disruptions, demonstrate the effect of disruptions on network components, and determine suppliers' share for the supply of raw materials.