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

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

Volume: 24

Author(s): SeyedAhmad SeyedAlinaghi, Amir Masoud Afsahi, Pegah Mirzapour, Arian Afzalian, Ramin Shahidi, Mohsen Dashti, Afsaneh Ghasemzadeh, Parinaz Paranjkhoo, Zahra Parsaei, Ava Pashaei, Parsa Mohammadi, Mohammad Sadeq Najafi, Sona Mahrokhi, Parisa Matini, Ali Moradi, Amirali Karimi, Solaiman Afroughi, Esmaeil Mehraeen*Omid Dadras

Affiliation:

• Khalkhal University of Medical sciences Health Information Management Khalkhal Iran

Keywords: COVID-19, SARS-CoV-2, Coronavirus disease 2019, Omicron subvariant, Delta Variant, Omicron new variant.

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.

Cite this article as:

SeyedAlinaghi SeyedAhmad, Afsahi Amir Masoud, Mirzapour Pegah, Afzalian Arian, Shahidi Ramin, Dashti Mohsen, Ghasemzadeh Afsaneh, Paranjkhoo Parinaz, Parsaei Zahra, Pashaei Ava, Mohammadi Parsa, Najafi Mohammad Sadeq, Mahrokhi Sona, Matini Parisa, Moradi Ali, Karimi Amirali, Afroughi Solaiman, Mehraeen Esmaeil*, Dadras Omid, Comparison of Omicron and Delta Variants of SARS-CoV-2: A Systematic Review of Current Evidence, Infectious Disorders - Drug Targets 2024; 24 () : e050324227686 . https://dx.doi.org/10.2174/0118715265279242240216114548