自2019年12月中国报告首例冠状病毒病例和首次SARS-CoV-2序列发布以来,该病毒经历了多次突变。在欧洲,春季疫情(3-4月)之后,病例数和死亡人数均有所下降。这种疾病可能已经演变成更温和的形式。2020年夏末PCR阳性病例的增加并没有导致预期的住院人数增加,ICU入院,和死亡,根据春季疾病的严重程度。这种疾病严重程度的差异可能是由于独立于病毒的因素或病毒的进化。这篇综述试图确定自大流行开始以来出现的突变及其在大流行的时间演变中的作用。在大部分人群中,普通感冒冠状病毒(HCoV)和SARS-CoV-2具有细胞和体液类型的交叉反应性。在编码与宿主免疫系统相互作用的蛋白质的SARS-CoV-2基因中出现了进化上重要的突变和缺失。此外,其中一个主要的突变(在病毒聚合酶中)在逻辑上与整个基因组中更高的突变频率相关。这种频率随着时间的推移而波动,并在流行病最活跃的时候显示出峰值。与免疫系统关系相关的蛋白质的突变率在第一次爆发后继续增加。一方面的交叉反应性和另一方面观察到的病毒突变可以解释直到2020年夏天的大流行的演变,部分原因是病毒相对于宿主免疫系统的进化。免疫接种运动于2020年12月开始:人们担心在2021年初循环疫苗可能逃脱。这些变体还可以逃避通过2020菌株感染获得的免疫力。
Since the reporting of the first cases of coronavirus in China and the publication of the first sequence of SARS-CoV-2 in December 2019, the virus has undergone numerous mutations. In Europe, the spring outbreak (March-April) was followed by a drop in the number of cases and deaths. The disease may have evolved into a milder form. The increase in PCR-positive cases in late summer 2020 did not lead to the expected increase in hospitalizations, ICU admissions, and deaths, based on the severity of the disease in the spring. This difference in disease severity could be due to factors independent of the virus or to the evolution of the virus. This
review attempts to identify the mutations that have appeared since the beginning of the pandemic and their role in the temporal evolution of the pandemic. There are a cell and humoral type cross-reactivity in a large part of the population to common cold coronaviruses (HCoVs) and SARS-CoV-2. Evolutionarily important mutations and deletions have emerged in the SARS-CoV-2 genes encoding proteins that interact with the host immune system. In addition, one of the major mutations (in viral polymerase) is logically associated with a higher frequency of mutations throughout the genome. This frequency fluctuates over time and shows a peak at the time when the epidemic was most active. The rate of mutations in proteins involved in the relationship to the immune system continues to increase after the first outbreak. The cross-reactivity on the 1 hand and the viral mutations observed on the other hand could explain the evolution of the pandemic until the summer of 2020, partly due to the evolution of the virus in relation to the host immune system. The immunization campaign began in December 2020: concerns are emerging about a possible escape of the circulating variants vaccines in early 2021. These variants could also escape immunity acquired through infection with the 2020 strains.