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Review
. 2022 Nov;69(6):3181-3197.
doi: 10.1111/tbed.14732. Epub 2022 Oct 20.

The origins of COVID-19 pandemic: A brief overview

Affiliations
Review

The origins of COVID-19 pandemic: A brief overview

Ying-Jian Hao et al. Transbound Emerg Dis. 2022 Nov.

Abstract

The novel coronavirus disease (COVID-19) outbreak that emerged at the end of 2019 has now swept the world for more than 2 years, causing immeasurable damage to the lives and economies of the world. It has drawn so much attention to discovering how the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated and entered the human body. The current argument revolves around two contradictory theories: a scenario of laboratory spillover events and human contact with zoonotic diseases. Here, we reviewed the transmission, pathogenesis, possible hosts, as well as the genome and protein structure of SARS-CoV-2, which play key roles in the COVID-19 pandemic. We believe the coronavirus was originally transmitted to human by animals rather than by a laboratory leak. However, there still needs more investigations to determine the source of the pandemic. Understanding how COVID-19 emerged is vital to developing global strategies for mitigating future outbreaks.

Keywords: SARS-CoV-2; genome similarities; laboratory origin; protein structure evolution; zoonotic origin.

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Conflict of interest statement

The authors declare that the work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Timeline of the emergence of SARS‐CoV‐2 mutants. D614G is the first determined variant that is prevalent in the world. In the past 2 years of the pandemic, approximately 551 million cases have been confirmed to date, with over 6 million deaths worldwide.
FIGURE 2
FIGURE 2
Schematic diagram of the transmission process of three HCoVs. Humans acquired SARS‐CoV and MERS‐CoV from bats through civet cats and dromedary camels, respectively. It is unclear how SARS‐CoV‐2 spread to humans.
FIGURE 3
FIGURE 3
Schematic diagram of the typical structure of coronavirus (80–120 nm), showing different structural proteins of the virus, i.e., S, M, E and genomic RNA encapsulated within the granule by the N protein.
FIGURE 4
FIGURE 4
Schematic diagrams of the spike proteins from three coronaviruses: pangolin coronavirus (PDB ID:7BBH, left), bat RaTG13 coronavirus (PDB ID:6ZGF, middle) and human SARS‐CoV‐2 Spike D614G variant (PDB ID:7EAZ, right). The N‐terminus is shown in blue, the middle sequence is pink and the C‐terminus is coloured by cyan, wheat, and light‐orange. The diagrams were based on Cryo‐EM data and visualized using PymoL software.

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References

    1. Al‐Qaaneh, A. M. , Alshammari, T. , Aldahhan, R. , Aldossary, H. , Alkhalifah, Z. A. , & Borgio, J. F. (2021). Genome composition and genetic characterization of SARS‐CoV‐2. Saudi Journal of Biological Sciences, 28(3), 1978–1989. 10.1016/j.sjbs.2020.12.053 - DOI - PMC - PubMed
    1. Amanat, F. , Thapa, M. , Lei, T. , Ahmed, S. M. S. , Adelsberg, D. C. , Carreno, J. M. , Strohmeier, S. , Schmitz, A. J. , Zafar, S. , Zhou, J. Q. , Rijnink, W. , Alshammary, H. , Borcherding, N. , Reiche, A. G. , Srivastava, K. , Sordillo, E. M. , van Bakel, H. , Personalized Virology, I. , Turner, J. S. , & Krammer, F. (2021). SARS‐CoV‐2 mRNA vaccination induces functionally diverse antibodies to NTD, RBD, and S2. Cell, 184(15), 3936–3948. e3910. 10.1016/j.cell.2021.06.005 - DOI - PMC - PubMed
    1. Amendola, A. , Bianchi, S. , Gori, M. , Colzani, D. , Canuti, M. , Borghi, E. , Raviglione, M. C. , Zuccotti, G. V. , & Tanzi, E. (2021). Evidence of SARS‐CoV‐2 RNA in an oropharyngeal swab specimen, Milan, Italy, early December 2019. Emerging Infectious Diseases, 27(2), 648–650. 10.3201/eid2702.204632 - DOI - PMC - PubMed
    1. Anand, N. M. , Liya, D. H. , Pradhan, A. K. , Tayal, N. , Bansal, A. , Donakonda, S. , & Jainarayanan, A. K. (2021). A comprehensive SARS‐CoV‐2 genomic analysis identifies potential targets for drug repurposing. PLoS One, 16(3), e0248553. 10.1371/journal.pone.0248553 - DOI - PMC - PubMed
    1. Andersen, K. G. , Rambaut, A. , Lipkin, W. I. , Holmes, E. C. , & Garry, R. F. (2020). The proximal origin of SARS‐CoV‐2. Nature Medicine, 26(4), 450–452. 10.1038/s41591-020-0820-9 - DOI - PMC - PubMed