COVID-19 is a pandemic of unprecedented proportions in recent human history. Less than 18 months since the onset of the pandemic, there are close to two hundred million confirmed cases and four million deaths worldwide. There have also been massive efforts geared towards finding safe and effective vaccines. By July 2021 there were 184 COVID-19 vaccine candidates in pre-clinical development, 105 in clinical development, and 18 vaccines approved for emergency use by at least one regulatory authority. These vaccines include whole virus live attenuated or inactivated, protein-based, viral vector, and nucleic acid vaccines. By mid-2021 three billion doses of COVID-19 vaccine have been administered around the world, mostly in high-income countries. COVID-19 vaccination provides hope for an end to the pandemic, if and only if there would be equal access and optimal uptake in all countries around the world.

COVID-19 是近代人类历史上规模空前的大流行病。新冠疫情爆发不到 18 个月，全球确诊病例近 2 亿，死亡病例近 400 万。还为寻找安全有效的疫苗做出了巨大努力。到 2021 年 7 月，有 184 种 COVID-19 候选疫苗处于临床前开发阶段，105 种处于临床开发阶段，还有 18 种疫苗被至少一个监管机构批准用于紧急使用。这些疫苗包括减毒或灭活的全病毒活疫苗、基于蛋白质的疫苗、病毒载体疫苗和核酸疫苗。到 2021 年年中，全球已接种了 30 亿剂 COVID-19 疫苗，其中大部分是在高收入国家。COVID-19 疫苗接种为结束大流行带来了希望，