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Review
. 2022 Jan 25;12(2):170.
doi: 10.3390/life12020170.

SARS-CoV-2 Variants and Clinical Outcomes: A Systematic Review

Indira R Mendiola-Pastrana  1 , Eduardo López-Ortiz  1 , José G Río de la Loza-Zamora  1 , James González  2 , Anel Gómez-García  3 , Geovani López-Ortiz  1
Affiliations
Review

SARS-CoV-2 Variants and Clinical Outcomes: A Systematic Review

Indira R Mendiola-Pastrana et al. Life (Basel). .

Abstract

Background: From the start of the COVID-19 pandemic, new SARS-CoV-2 variants have emerged that potentially affect transmissibility, severity, and immune evasion in infected individuals. In the present systematic review, the impact of different SARS-CoV-2 variants on clinical outcomes is analyzed.

Methods: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020. Two databases (PubMed and ScienceDirect) were searched for original articles published from 1 January 2020 to 23 November 2021. The articles that met the selection criteria were appraised according to the Newcastle-Ottawa Quality Assessment Scale.

Results: Thirty-three articles were included, involving a total of 253,209 patients and 188,944 partial or complete SARS-CoV-2 sequences. The most reported SARS-CoV-2 variants showed changes in the spike protein, N protein, RdRp and NSP3. In 28 scenarios, SARS-CoV-2 variants were found to be associated with a mild to severe or even fatal clinical outcome, 15 articles reported such association to be statistically significant. Adjustments in eight of them were made for age, sex and other covariates.

Conclusions: SARS-CoV-2 variants can potentially have an impact on clinical outcomes; future studies focused on this topic should consider several covariates that influence the clinical course of the disease.

Keywords: SARS-CoV-2 variants; clinical outcomes; clinical presentations; health care; mutations; outcome assessment; severity.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
PRISMA flow diagram for search strategy.
Figure 2
Figure 2
Main changes in spike protein reported in articles analyzed. ● Protomer of the spike protein; ● RBD; ● RBM; ● amino acid substitutions, ● ACE2 protein, (PDB structure [37,38], PyMOL v.4.6).
See this image and copyright information in PMC

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