Omicron variant (B.1.1.529) of SARS-CoV-2: Mutation, infectivity, transmission, and vaccine resistance

Abstract

The appearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant Omicron (B.1.1.529) has caused panic responses around the world because of its high transmission rate and number of mutations. This review summarizes the highly mutated regions, the essential infectivity, transmission, vaccine breakthrough and antibody resistance of the Omicron variant of SARS-CoV-2. The Omicron is highly transmissible and is spreading faster than any previous variant, but may cause less severe symptoms than previous variants. The Omicron is able to escape the immune system's defenses and coronavirus disease 2019 vaccines are less effective against the Omicron variant. Early careful preventive steps including vaccination will always be key for the suppression of the Omicron variant.

Keywords: COVID-19; Genotyping; Infectivity; Omicron variant B.1.1.529; RT-PCR; SARS-CoV-2; Transmission; Variant of concern.

Figure 1

Linear trend of number of severe acute respiratory syndrome coronavirus 2 infected cases (January 22, 2020 to December 21, 2021). Source: https://www.worldometers.info/coronavirus/#countries.

Figure 2

Trend of number of people who died from severe acute respiratory syndrome coronavirus 2 (January 22, 2020 to December 21, 2021). Source: https://www.worldometers.info/coronavirus/#countries.

Figure 3

Daily new confirmed severe acute respiratory syndrome coronavirus 2 infected cases (January 22, 2020 to December 21, 2021). Source: https://www.worldometers.info/coronavirus/#countries.

Figure 4

Daily new deaths due to coronavirus disease 2019 (January 22, 2020 to December 21, 2021). Source: https://www.worldometers.info/coronavirus/#countries.

Figure 5

Number of severe acute respiratory syndrome coronavirus 2 Omicron variant cases worldwide as of December 16, 2021. Source: https://www.statista.com/statistics/1279100/number-omicron-variant-worldwide-by-country/.

Figure 6

Comparison of structure of spike protein between the Omicron and the Delta of severe acute respiratory syndrome coronavirus 2 issued by Italy Bambino Gesù Children Hospital showing the active site in orange and the residues colored against different mutational rates. Source: https://new.qq.com/rain/a/20211214A087SY00?refer=wx_hot.

Figure 7

Immunoflurescence imaging. A: The cultured Vero E6 cell with no infection of the Omicron variant; B: The Omicron variant PN protein on spike proteins at 24-h after infection of the Omicron virus; C: The Omicron variant PN protein on spike proteins at 48-h after infection of the Omicron virus, red florescence indicating the staining of antigen of Omicron in the infected Vero E6 cells. Source: https://m.thepaper.cn/baijiahao_15655744.