BACKGROUND The COVID-19 pandemic demanded a global effort towards quickly developing safe and effective vaccines against SARS-CoV-2. OBJECTIVE This review aimed to discuss the main vaccines available, their mechanisms of action, results of clinical trials, and epidemiological behavior. The implications of viral variants were also debated. METHODS A non-systematic literature review was performed between February and March 2021 by searching the Pubmed, Scopus, and SciELO databases, using different combinations of the following terms: "vaccines", "clinical trials" , "SARS-CoV-2", "Coronavirus", "COVID-19", "mechanisms of action". Data regarding clinical trials of SARS-CoV-2 vaccines and epidemiological information were also searched. RESULTS The mechanisms of action included vector-virus, mRNA and inactivated virus vaccines. The vaccines showed positive results in phases 2/3 clinical trials. The efficacy of the mRNA 1273 and of mRNA BNT 162b2 vaccines were 94.1% and 95%, respectively. The effectiveness of the ChAdOx1 nCoV-19 vaccine varied according to the scheme, with an overall value of 70.4%. The Gam-COVID-Vac vaccine had an efficacy of 91.6%. Regarding the Ad26.COV2.S vaccine, 99% or more of seroconversion was observed in all subgroups 29 days after vaccination. The CoronaVac vaccine induced an immune response in 92% of the volunteers receiving 3ug and in 98% with 6ug, in comparison to 3% in the placebo group. CONCLUSION Global efforts have resulted in vaccines being available in record time, with good safety and immunogenicity profile. However, only long-term studies can provide more information on the duration of immunity and the need for additional doses.

中文翻译：

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全球疫苗接种对 SARS-CoV-2 感染的影响：疫苗机制、临床试验结果、疫苗覆盖率和与新变种相互作用的综述。

背景 COVID-19 大流行要求全球努力快速开发针对 SARS-CoV-2 的安全有效的疫苗。目的 本综述旨在讨论可用的主要疫苗、它们的作用机制、临床试验结果和流行病学行为。病毒变体的影响也引起了争论。方法 在 2021 年 2 月至 2021 年 3 月期间，通过搜索 Pubmed、Scopus 和 SciELO 数据库，使用以下术语的不同组合进行了非系统性文献回顾：“疫苗”、“临床试验”、“SARS-CoV-2”、 “冠状病毒”、“COVID-19”、“作用机制”。还检索了有关 SARS-CoV-2 疫苗临床试验和流行病学信息的数据。结果 作用机制包括载体病毒、mRNA和灭活病毒疫苗。这些疫苗在 2/3 期临床试验中显示出积极的结果。mRNA 1273 和 mRNA BNT 162b2 疫苗的效力分别为 94.1% 和 95%。ChAdOx1 nCoV-19 疫苗的有效性因方案而异，总体值为 70.4%。Gam-COVID-Vac 疫苗的功效为 91.6%。关于 Ad26.COV2.S 疫苗，接种后 29 天，在所有亚组中观察到 99% 或更多的血清转化。CoronaVac 疫苗在 92% 接受 3ug 的志愿者和 98% 接受 6ug 的志愿者中诱导了免疫反应，而安慰剂组为 3%。结论 全球努力已导致疫苗在创纪录的时间内上市，具有良好的安全性和免疫原性。然而，