School of Human Sciences, London Metropolitan Universitygrid.23231.31 and National Heart and Lung Institute, Imperial College London, London, United Kingdom.
Louisiana State University Health, Shreveport, Louisiana, USA.
mBio. 2022 Apr 26;13(2):e0297921. doi: 10.1128/mbio.02979-21. Epub 2022 Mar 30.
The emergence of several new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in recent months has raised concerns around the potential impact on ongoing vaccination programs. Data from clinical trials and real-world evidence suggest that current vaccines remain highly effective against the alpha variant (B.1.1.7), while some vaccines have reduced efficacy and effectiveness against symptomatic disease caused by the beta variant (B.1.351) and the delta variant (B.1.617.2); however, effectiveness against severe disease and hospitalization caused by delta remains high. Although data on the effectiveness of the primary regimen against omicron (B.1.1.529) are limited, booster programs using mRNA vaccines have been shown to restore protection against infection and symptomatic disease (regardless of the vaccine used for the primary regimen) and maintain high effectiveness against hospitalization. However, effectiveness against infection and symptomatic disease wanes with time after the booster dose. Studies have demonstrated reductions of varying magnitude in neutralizing activity of vaccine-elicited antibodies against a range of SARS-CoV-2 variants, with the omicron variant in particular exhibiting partial immune escape. However, evidence suggests that T-cell responses are preserved across vaccine platforms, regardless of variant of concern. Nevertheless, various mitigation strategies are under investigation to address the potential for reduced efficacy or effectiveness against current and future SARS-CoV-2 variants, including modification of vaccines for certain variants (including omicron), multivalent vaccine formulations, and different delivery mechanisms.
近几个月来，几种严重急性呼吸综合征冠状病毒 2 型（SARS-CoV-2）的新变体的出现引起了人们对其对正在进行的疫苗接种计划潜在影响的关注。临床试验和真实世界证据的数据表明，目前的疫苗仍然对 alpha 变体（B.1.1.7）高度有效，而一些疫苗对 beta 变体（B.1.351）和 delta 变体（B.1.617.2）引起的有症状疾病的疗效和有效性降低；然而，delta 变体引起的严重疾病和住院的疗效仍然很高。虽然关于针对 omicron（B.1.1.529）的主要方案疗效的数据有限，但使用 mRNA 疫苗的加强针方案已被证明可恢复对感染和有症状疾病的保护（无论主要方案使用哪种疫苗），并保持对住院的高疗效。然而，加强针剂量后，随着时间的推移，对感染和有症状疾病的疗效会减弱。研究表明，针对一系列 SARS-CoV-2 变体的疫苗诱导抗体的中和活性有不同程度的降低，特别是 omicron 变体表现出部分免疫逃逸。然而，有证据表明，无论关注的变体如何，T 细胞反应在各种疫苗平台上都得到了保留。尽管如此，仍在研究各种缓解策略以应对当前和未来 SARS-CoV-2 变体的疗效或有效性降低的可能性，包括针对某些变体（包括 omicron）修改疫苗、多价疫苗配方和不同的传递机制。
