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SARS — beginning to understand a new virus

Key Points

  • A new infectious disease, called severe acute respiratory syndrome (SARS), appeared in southern China in 2002. During the period from November 2002 to the summer of 2003, the World Health Organization recorded 8098 probable SARS cases and 774 deaths in 29 countries.

  • A previously unknown coronavirus was isolated from FRhK-4 and Vero E6 cells inoculated with clinical specimens from patients. A virus with close homology to SARS-CoV was isolated from palm civets and racoon dogs, which are used as food in southern China

  • In less than a month from the first indication that a coronavirus might be implicated in the disease, the nucleotide sequence of the virus was available, and diagnostic tests were set up.

  • The phylogenetic analysis of the SARS-CoV genome revealed that the virus is distinct from the three known groups of coronaviruses and represents an early split-off from group 2.

  • The development of antiviral drugs or vaccines is being investigated. Viral enzymes essential for virus replication, such as the RNA-dependent RNA polymerase (RdRp), the 3C-like cystein protease (3Clpro) and the helicases are the most attractive targets for antiviral molecules. Of the possible vaccine targets, the spike (S) protein represents the most promising one.

  • So far, β-interferon is the only licensed drug available, which has been reported to interfere with virus replication in vitro. Should SARS return during the next winter, we will still need to rely mostly on quarantine measures to contain it.

Abstract

The 114-day epidemic of the severe acute respiratory syndrome (SARS) swept 29 countries, affected a reported 8,098 people, left 774 patients dead and almost paralysed the Asian economy. Aggressive quarantine measures, possibly aided by rising summer temperatures, successfully terminated the first eruption of SARS and provided at least a temporal break, which allows us to consolidate what we have learned so far and plan for the future. Here, we review the genomics of the SARS coronavirus (SARS-CoV), its phylogeny, antigenic structure, immune response and potential therapeutic interventions should the SARS epidemic flare up again.

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Figure 1: Morphology of the SARS coronavirus.
Figure 2: Genome structure of SARS coronavirus.
Figure 3: Comparison of coronavirus genome structures.
Figure 4: Molecular relationship of 20 SARS genomes.
Figure 5: Relationship between SARS-CoV and other coronaviruses using different phylogenetic strategies.
Figure 6: The S1 domain of SARS-CoV spike is structurally related to group 2 coronaviruses.

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Acknowledgements

The authors are grateful to the Fonds der Chemischen Industrie and the Chiron Vaccines Cellular Microbiology and Bioinformatics Unit for their continuous support.

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Correspondence to Rino Rappuoli.

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S. Abrignani, R. Rappuoli, K. Stadler and V. Masignani are employed by Chiron Corporation.

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Stadler, K., Masignani, V., Eickmann, M. et al. SARS — beginning to understand a new virus. Nat Rev Microbiol 1, 209–218 (2003). https://doi.org/10.1038/nrmicro775

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