Vaccine distribution is a complex supply-chain problem because vaccines need to reach healthcare facilities in the required quantities while maintaining appropriate cold-chain conditions and keeping distribution costs under control. This project examines the use of Operations Research in vaccine cold-chain distribution through two published studies. Lin, Zhao and Lev (2020) study the choice between cold-chain and non-cold-chain transportation, while Sripada et al. (2023) develop a multi-tier decision-support framework for vaccine distribution. Drawing on these studies, a simplified capacitated network-flow model is developed for a distribution network linking a manufacturer, a state vaccine store, district stores and primary health centres. The model minimizes transportation cost, refrigerated vehicle-trip cost and shortage cost subject to supply, capacity, demand and vehicle-capacity constraints. In the base case, 4,600 doses are distributed without shortage at a total cost of ₹30,035. Sensitivity analysis is then used to examine changes in supply, demand and vehicle-related parameters. The results show how Operations Research can support practical, cost-conscious distribution decisions, while also highlighting the additional complexity created by uncertainty, inventory, expiry and cold-chain failure risk.