Vaccines provide powerful tools to mitigate the enormous public health and economic costs that the ongoing SARS-CoV-2 pandemic continues to exert globally, yet vaccine distribution remains unequal among countries. To examine the potential epidemiological and evolutionary impacts of ‘vaccine nationalism’, we extend previous models to include simple scenarios of stockpiling between two regions. In general, when vaccines are widely available and the immunity they confer is robust, sharing doses minimizes total cases across regions. A number of subtleties arise when the populations and transmission rates in each region differ, depending on evolutionary assumptions and vaccine availability. When the waning of natural immunity contributes most to evolutionary potential, sustained transmission in low access regions results in an increased potential for antigenic evolution, which may result in the emergence of novel variants that affect epidemiological characteristics globally. Overall, our results stress the importance of rapid equitable vaccine distribution for global control of the pandemic.

中文翻译：

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疫苗民族主义与 SARS-CoV-2 的动态和控制

疫苗提供了强大的工具来减轻持续的 SARS-CoV-2 大流行继续在全球范围内造成的巨大公共卫生和经济成本，但各国之间的疫苗分配仍然不平等。为了检查“疫苗民族主义”的潜在流行病学和进化影响，我们扩展了以前的模型，以包括两个地区之间的简单储存情景。一般来说，当疫苗广泛可用并且它们赋予的免疫力很强时，共享剂量可以最大限度地减少跨地区的总病例数。当每个地区的人口和传播率不同时，就会出现许多微妙之处，这取决于进化假设和疫苗可用性。当自然免疫力的减弱对进化潜力贡献最大时，在低获取区域的持续传播导致抗原进化的可能性增加，这可能导致影响全球流行病学特征的新变异的出现。总体而言，我们的结果强调了快速公平分配疫苗对于全球大流行控制的重要性。