摘要
BACKGROUND Omicron(B.1.1.529)is a severe acute respiratory syndrome coronavirus 2(SARSCoV-2)variant of concern;however,there is no comprehensive analysis regarding clinical features,disease severity,or clinical outcomes of this variant.AIM To compare the clinical characteristics of infection with omicron and previous variants of SARS-CoV-2.METHODS We searched major international databases consisting ISI Web of Science,PubMed,Scopus,MedRxiv,and Reference Citation Analysis to collect the potential relevant documents.Finally,clinical features,e.g.,death rate,intensive care unit(ICU)admission,length of hospitalization,and mechanical ventilation,of infection with SARS-CoV-2 omicron variant compared with previous variants were assessed using odds ratio and 95%confidence intervals by Comprehensive Meta-Analysis software version 2.2.RESULTS A total of 12 articles met our criteria.These investigated the clinical outcomes of infection with omicron variant compared with other variants such as alpha,beta and delta.Our results suggested that ICU admission,need for mechanical ventilation,and death rate were significantly lower for omicron than previous variants.In addition,the average length of hospitalization during the omicron wave was significantly shorter than for other variants.CONCLUSION The infectivity of omicron variant was higher than for previous variants due to several mutations,particularly in the spike protein.However,disease severity was mild to moderate compared previous variants.
