Comparison of Omicron and Delta Variants of SARS-CoV-2: A Systematic Review of Current Evidence

  • Authors: SeyedAlinaghi S.1, Afsahi A.M.2, Mirzapour P.1, Afzalian A.3, Shahidi R.4, Dashti M.5, Ghasemzadeh A.5, Paranjkhoo P.6, Parsaei Z.7, Pashaei A.8, Mohammadi P.9, Najafi M.S.10, Mahrokhi S.1, Matini P.11, Moradi A.9, Karimi A.9, Afroughi S.12, Mehraeen E.13, Dadras O.14
  • Affiliations:
    1. Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences
    2. Department of Radiology, School of Medicine,, University of California, San Diego
    3. School of medicine, Tehran University of Medical Sciences
    4. School of medicine, Bushehr University of Medical Sciences
    5. Department of Radiology, Tabriz University of Medical Sciences
    6. Turpanjian College of Health Sciences, American University of Armenia
    7. Health Information Technology Research Center, Isfahan University of Medical Sciences
    8. School of Nursing, University of British Columbia
    9. School of Medicine, Tehran University of Medical Sciences
    10. Research Center for Advanced Technologies in Cardiovascular Medicine, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences
    11. School of Medicine, Iran University of Medical Sciences
    12. Department of Biostatistics and Epidemiology, School of Health and Social Determinants of Health Research Center, Yasuj University of Medical Sciences
    13. Department of Health Information Technology, Khalkhal University of Medical sciences
    14. Department of Global Public Health and Primary Care, University of Bergen
  • Issue: Vol 24, No 7 (2024)
  • Section: Medicine
  • URL: https://vietnamjournal.ru/1871-5265/article/view/645741
  • DOI: https://doi.org/10.2174/0118715265279242240216114548
  • ID: 645741

Cite item

Full Text

Abstract

Introduction:Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) caused the outbreak of coronavirus disease 2019 (COVID-19) in late 2019 in Wuhan, China. In early 2020, the disease spread rapidly around the world. Since the pandemic, SARS-CoV-2 has evolved dramatically into a wide variety of variants endowed with devastating properties. As of March 6, 2022, five SARS-CoV-2 variants of concern, including Alpha, Beta, Gamma, Delta, and Omicron strains have been identified. Due to the crucial importance of understanding the differences between the Omicron and Delta variants, this systematic review was conducted.

Methods:This systematic review investigated new variants of Omicron SARS-CoV-2 based on cur-rent studies. Online databases were searched for English articles as of January 03, 2023. Selection of publications was a two-step process of title/abstract and full-text assessment against eligibility crite-ria. The relevant data from the included articles were systematically collected and organized in a designed table for analysis. To ensure the quality of the review, the PRISMA checklist and Newcas-tle-Ottawa Scale (NOS) of quality assessment were utilized.

Results:The data extracted from 58 articles were analyzed, including 10003 pieces of evidence. Lower risk of hospitalization, ICU admission, and mortality after vaccination were reported in the Omicron variant compared to the Delta variant. Additionally, the Delta variant led to more severe clinical symptoms in comparison to the Omicron variant.

Conclusion:The Omicron variant of SARS-CoV-2 results in less severe disease outcomes as com-pared to Delta. Nevertheless, it remains crucial to maintain ongoing monitoring, implement contain-ment measures, and adapt vaccination protocols to effectively address the evolving variants.

About the authors

SeyedAhmad SeyedAlinaghi

Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences

Email: info@benthamscience.net

Amir Masoud Afsahi

Department of Radiology, School of Medicine,, University of California, San Diego

Email: info@benthamscience.net

Pegah Mirzapour

Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences

Email: info@benthamscience.net

Arian Afzalian

School of medicine, Tehran University of Medical Sciences

Email: info@benthamscience.net

Ramin Shahidi

School of medicine, Bushehr University of Medical Sciences

Email: info@benthamscience.net

Mohsen Dashti

Department of Radiology, Tabriz University of Medical Sciences

Email: info@benthamscience.net

Afsaneh Ghasemzadeh

Department of Radiology, Tabriz University of Medical Sciences

Email: info@benthamscience.net

Parinaz Paranjkhoo

Turpanjian College of Health Sciences, American University of Armenia

Email: info@benthamscience.net

Zahra Parsaei

Health Information Technology Research Center, Isfahan University of Medical Sciences

Email: info@benthamscience.net

Ava Pashaei

School of Nursing, University of British Columbia

Email: info@benthamscience.net

Parsa Mohammadi

School of Medicine, Tehran University of Medical Sciences

Email: info@benthamscience.net

Mohammad Sadeq Najafi

Research Center for Advanced Technologies in Cardiovascular Medicine, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences

Email: info@benthamscience.net

Sona Mahrokhi

Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences

Email: info@benthamscience.net

Parisa Matini

School of Medicine, Iran University of Medical Sciences

Email: info@benthamscience.net

Ali Moradi

School of Medicine, Tehran University of Medical Sciences

Email: info@benthamscience.net

Amirali Karimi

School of Medicine, Tehran University of Medical Sciences

Email: info@benthamscience.net

Solaiman Afroughi

Department of Biostatistics and Epidemiology, School of Health and Social Determinants of Health Research Center, Yasuj University of Medical Sciences

Email: info@benthamscience.net

Esmaeil Mehraeen

Department of Health Information Technology, Khalkhal University of Medical sciences

Author for correspondence.
Email: info@benthamscience.net

Omid Dadras

Department of Global Public Health and Primary Care, University of Bergen

Email: info@benthamscience.net

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