Unbalanced global vaccine product trade pattern: A network perspective.

Mass vaccination is the most cost-effective intervention in response to public health events. Thus, equitable access to vaccine products is essential to ensure global human health. Based on the global vaccine product trade data from 2000 to 2018 and employing social network analysis, this paper explores the unbalanced pattern of global vaccine product trade and assesses the sensitivity interdependence between countries. Overall, the analysis shows that global vaccine product trade links have long been highly concentrated within developed countries in Europe and America. Nevertheless, with the rise of global and regional hub countries, the global vaccine product trade network has begun to evolve from a unipolar structure with the U.S. as the sole core to a multipolar structure with the U.S. and Western European countries as the core. Meanwhile, emerging countries, represented by China and India, are increasingly participating in the global vaccine product trade network and are beginning to play an important role. The formation of this multipolar pattern has provided countries in the Global South with more options for cooperation in the vaccine product trade and reduces the sensitivity interdependence of network periphery countries on core countries, which consequently reduces the global supply risk of vaccine products.