With multiple candidate vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entering efficacy testing, researchers and ethicists should come to grips with the distinctive medical ethics questions that could arise. An important one is determining the most ethical way to proceed when comparing a purportedly promising vaccine against a purportedly less-promising one. Imagine a situation in which neither vaccine is proven; one or both could fail. But one does look promising, and more promising than the alternative vaccine, as agreed by all informed experts.

中文翻译：

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意见：将有希望的冠状病毒疫苗与不太有前景的疫苗进行测试是符合道德的。

随着多种针对严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）的候选疫苗进入功效测试，研究人员和伦理学家应着手应对可能出现的独特医学伦理学问题。重要的是，在将一种据称有前途的疫苗与一种据称不太有前景的疫苗进行比较时，确定最符合道德的方法。设想一种情况，其中两种疫苗均未得到证实；一个或两个都可能失败。但是，正如所有知情专家所同意的那样，它的确看起来很有希望，而且比替代疫苗更有希望。