Despite the worldwide vaccination, the COVID-19 pandemic continues as SARS-CoV-2 evolves into numerous variants. Since the first identification of the novel SARS-CoV-2 variant of concern (VOC) Omicron on November 24th, 2021, from an immunocompromised patient in South Africa, the variant has overtaken Delta as the predominant lineage in South Africa and has quickly spread to over 40 countries.Here, we provide an initial molecular characterization of the Omicron variant through analyzing a large number of mutations, especially in the spike protein receptor-binding domain with their potential effects on viral infectivity and host immunity. Our analysis indicates that the Omicron variant has two subclades and may evolve from clade 20B instead of the currently dominant Delta variant. In addition, we have also identified mutations that may affect the ACE2 receptor and/ or antibody bindings. Our study has raised additional questions on the evolution, transmission, virulence, and immune escape properties of this new Omicron variant.

Initially isolated in 1947, Zika virus (ZIKV) has recently emerged as significant public health concern. Sequence analysis of all 41 known ZIKV RNA open reading frames to date indicates that ZIKV has undergone significant changes in both protein and nucleotide sequences during the past half century.

Monkeypox virus (MPXV) has generally circulated in West and Central Africa since its emergence. Recently, sporadic MPXV infections in several nonendemic countries have attracted widespread attention. Here, we conducted a systematic analysis of the recent outbreak of MPXV‐2022, including its genomic annotation and molecular evolution. The phylogenetic analysis indicated that the MPXV‐2022 strains belong to the same lineage of the MPXV strain isolated in 2018. However, compared with the MPXV strain in 2018, in total 46 new consensus mutations were observed in the MPXV‐2022 strains, including 24 nonsynonymous mutations. By assigning mutations to 187 proteins encoded by the MPXV genome, we found that 10 proteins in the MPXV are more prone to mutation, including D2L‐like, OPG023, OPG047, OPG071, OPG105, OPG109, A27L‐like, OPG153, OPG188, and OPG210 proteins. In the MPXV‐2022 strains, four and three nucleotide substitutions are observed in OPG105 and OPG210, respectively. Overall, our studies illustrated the genome evolution of the ongoing MPXV outbreak and pointed out novel mutations as a reference for further studies.