Cold chain transportation decision in the vaccine supply chain

Vaccines are a special kind of drug, the quality of which is highly sensitive to temperature and directly related to public health. Recently, numerous vaccine-related adverse events have occurred in the world, especially in developing countries, due to vaccines being exposed to inappropriate temperatures during their transportation. This paper considers the vaccine supply chain including a distributor and a retailer (hospital or clinic). The distributor decides to use a cold chain or non-cold chain to transport the vaccines. The retailer performs an inspection when receiving the vaccines. First, a basic model is developed to study the conditions under which the distributor will transport the vaccines via a cold chain or non-cold chain. Then, two common inspection policies (a single-step one and a two-step one) are introduced into the basic model to explore the impact of the retailer's inspection at the end of transportation on the distributor's original decision. We show that the retailer's single-step inspection influences the distributor to choose the cold chain option. Interestingly, we prove that the two-step inspection policy is less effective than the single-step one in this effect. We suggest that the retailer's role in improving the distributor's non-cold chain transportation behavior should be fully used.