Omicron SARS-CoV-2 variant of concern: A review on its transmissibility, immune evasion, reinfection, and severity.
Journal
Medicine
ISSN: 1536-5964
Titre abrégé: Medicine (Baltimore)
Pays: United States
ID NLM: 2985248R
Informations de publication
Date de publication:
13 May 2022
13 May 2022
Historique:
received:
08
02
2022
accepted:
07
03
2022
entrez:
18
5
2022
pubmed:
19
5
2022
medline:
21
5
2022
Statut:
epublish
Résumé
Omicron, the new Covid-19 variant, has already become dominant in many countries and is spreading at an unprecedented speed. The objective of this study was to review the existing literature on Omicron's transmissibility, immune evasion, reinfection, and severity.A literature search was performed using "PubMed," "Web of Science," "Scopus," "ScienceDirect," "Google Scholar," "medRxiv," and "bioRxiv." Data were extracted from articles that reported at least one of the following: transmissibility, immune evasion, reinfection, and severity related to Omicron.We found that Omicron spread faster than any other variant. This higher transmissibility can be ascribed to its extraordinary ability to evade the immunity developed by both vaccination and previous infections. However, we found that infections by Omicron were significantly less severe than those caused by Delta and other previous variants. We observed a significantly lower incidence of hospitalization, intensive care unit admission, and mechanical ventilator use in Omicron infections than in Delta or other variants. A substantially shorter median hospital stay and lower fatality rate were also observed in the Omicron infections. Despite Omicron's higher potential to evade immunity, vaccines and booster shots were found to be still significantly effective in protecting against severe Covid-19 infections.Omicrons may be less severe than other variants of concern. However, its immune evasiveness and rapid spread pose an enormous threat to the global healthcare system.
Identifiants
pubmed: 35583528
doi: 10.1097/MD.0000000000029165
pii: 00005792-202205130-00004
pmc: PMC9276130
doi:
Types de publication
Journal Article
Review
Langues
eng
Sous-ensembles de citation
IM
Pagination
e29165Informations de copyright
Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.
Déclaration de conflit d'intérêts
The authors have no funding and conflicts of interests to disclose.
Références
“Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern”. Available at: https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern . Accessed January 13, 2022.
Callaway E. Heavily mutated Omicron variant puts scientists on alert. Nature 2021;600:21–121.
“Enhancing response to Omicron SARS-CoV-2 variant.” Available at: https://www.who.int/publications/m/item/enhancing-readiness-for-omicron-(b.1.1.529)-technical-brief-and-priority-actions-for-member-states . Accessed January 13, 2022.
Wolter N, et al. , “Early assessment of the clinical severity of the SARS-CoV-2 Omicron variant in South Africa,” Infectious Diseases (except HIV/AIDS), preprint, Dec. 2021. doi: 10.1101/2021.12.21.21268116.
CDC. COVID data tracker. Centers for Disease Control and Prevention 2020; https://covid.cdc.gov/covid-data-trackerhttps://covid.cdc.gov/covid-data-tracker . Accessed January 13, 2022).
Shumaker L. U.S. reports 1.35 million COVID-19 cases in a day, shattering global record. Reuters 2022;[Online]. Available: https://www.reuters.com/business/healthcare-pharmaceuticals/us-reports-least-11-mln-covid-cases-day-shattering-global-record-2022-01-11/ . Accessed: January 13, 2022.
Brandal LT, et al. Outbreak caused by the SARS-CoV-2 Omicron variant in Norway, November to December 2021. Euro Surveill Bull Eur Sur Mal Transm Eur Commun Dis Bull 2021;26: doi: 10.2807/1560-7917.ES.2021.26.50.2101147.
doi: 10.2807/1560-7917.ES.2021.26.50.2101147
F. P. Lyngse et al. , “SARS-CoV-2 Omicron VOC Transmission in Danish Households,” Infectious Diseases (except HIV/AIDS), preprint, Dec. 2021. doi: 10.1101/2021.12.27.21268278.
Lewnard JA, Hong VX, Patel MM, Kahn R, Lipsitch M, Tartof SY, “Clinical outcomes among patients infected with Omicron (B.1.1.529) SARS-CoV-2 variant in southern California,” Epidemiology, preprint, Jan. 2022. doi: 10.1101/2022.01.11.22269045.
Pulliam JRC, et al. , “Increased risk of SARS-CoV-2 reinfection associated with emergence of the Omicron variant in South Africa,” Epidemiology, preprint, Nov. 2021. doi: 10.1101/2021.11.11.21266068.
Nemet I, Kliker L, Lustig Y, et al. Third BNT162b2 vaccination neutralization of SARS-CoV-2 Omicron infection. N Engl J Med 2021;NEJMc2119358doi: 10.1056/NEJMc2119358.
doi: 10.1056/NEJMc2119358
Schmidt F, Muecksch F, Weisblum Y, et al. Plasma neutralization of the SARS-CoV-2 Omicron variant. N Engl J Med 2021;NEJMc2119641doi: 10.1056/NEJMc2119641.
doi: 10.1056/NEJMc2119641
Collie S, Champion J, Moultrie H, Bekker L-G, Gray G. Effectiveness of BNT162b2 vaccine against Omicron variant in South Africa. N Engl J Med 2021;NEJMc2119270doi: 10.1056/NEJMc2119270.
doi: 10.1056/NEJMc2119270
H. F. Tseng, et al., “Effectiveness of mRNA-1273 against SARS-CoV-2 omicron and delta variants,” Infectious Diseases (except HIV/AIDS), preprint, Jan. 2022. doi: 10.1101/2022.01.07.22268919.
N. Andrews, et al., “Effectiveness of COVID-19 vaccines against the Omicron (B.1.1.529) variant of concern,” Epidemiology, preprint, Dec. 2021. doi: 10.1101/2021.12.14.21267615.
Sheikh A, Kerr S, Woolhouse M, McMenamin J, Robertson C, “Severity of Omicron variant of concern and vaccine effectiveness against symptomatic disease: national cohort with nested test negative design study in Scotland,” December 2021. [Online]. Available: https://www.research.ed.ac.uk/en/publications/severity-of-omicron-variant-of-concern-and-vaccine-effectiveness- . Accessed: January 14, 2022
Altarawneh HN, et al. Protection against the Omicron variant from previous SARS-CoV-2 infection. N Engl J Med 2022;0:nulldoi: 10.1056/NEJMc2200133.
doi: 10.1056/NEJMc2200133
Abdullah F, Myers J, Basu D, et al. Decreased severity of disease during the first global omicron variant covid-19 outbreak in a large hospital in Tshwane, South Africa. Int J Infect Dis 2022;116:38–42.
“Report 50 - Hospitalisation risk for Omicron cases in England,” Imperial College London . Available at: http://www.imperial.ac.uk/medicine/departments/school-public-health/infectious-disease-epidemiology/mrc-global-infectious-disease-analysis/covid-19/report-50-severity-omicron/ . Accessed January 15, 2022.
L. Wang, N. A. Berger, D. C. Kaelber, P. B. Davis, N. D. Volkow, and R. Xu, “Comparison of outcomes from COVID infection in pediatric and adult patients before and after the emergence of Omicron,” Infectious Diseases (except HIV/AIDS), preprint, Jan. 2022. doi: 10.1101/2021.12.30.21268495.
J. A. Hay et al. , “Viral dynamics and duration of PCR positivity of the SARS-CoV-2 Omicron variant,” Epidemiology, preprint, Jan. 2022. doi: 10.1101/2022.01.13.22269257.
Accorsi EK, Britton A, Fleming-Dutra KE, et al. Association between 3 doses of mRNA COVID-19 vaccine and symptomatic infection caused by the SARS-CoV-2 Omicron and delta variants. JAMA 2022;327:639–51.
Chan MCW, et al. , “SARS-CoV-2 Omicron variant replication in human respiratory tract ex vivo,” In Review, preprint, Dec. 2021. doi: 10.21203/rs.3.rs-1189219/v1.
R. Abdelnabi et al. , “The omicron (B.1.1.529) SARS-CoV-2 variant of concern does not readily infect Syrian hamsters,” Microbiology, preprint, Dec. 2021. doi: 10.1101/2021.12.24.474086.