Infection and Drug Resistance (Apr 2022)
Mutational Pattern, Impacts and Potential Preventive Strategies of Omicron SARS-CoV-2 Variant Infection
Abstract
Endeshaw Chekol Abebe,1 Markeshaw Tiruneh G/Medhin,2 Awgichew Behaile T/Mariam,1 Tadesse Asmamaw Dejenie,2 Teklie Mengie Ayele,3 Fitalew Tadele Admasu,1 Zelalem Tilahun Muche,4 Getachew Asmare Adela5 1Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia; 2Department of Medical Biochemistry, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia; 3Department of Pharmacy, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia; 4Department of Physiology, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia; 5Department of Reproductive Health and Nutrition, School of Public Health, Wolaita Sodo University, Wolaita Sodo, EthiopiaCorrespondence: Endeshaw Chekol Abebe, Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, P. O. Box: 272, Debre Tabor, 6300, Ethiopia, Tel +251928428133, Email [email protected]: Since the emergence of COVID 19, the authentic SARS-CoV-2 has evolved into a range of novel variants that are of more global concern. In late November 2021, the Omicron (lineage B.1.1.529) variant was identified as a new variant and considered as the fifth variant of concern. Omicron harbors a genetic profile that is exceedingly unusual, with a huge number of mutations. Above thirty mutations are localized in the S protein, while some are found in other structural and non-structural proteins. Half of the mutations in the S protein are in the RBD, which is a major target of antibodies, showing that Omicron mutations may affect antibody binding affinity to the S protein. The Omicron variant has been found to result in immune escape, therapeutic or vaccine escape, as well as increased transmissibility and reinfection risk, explaining its rapid international spread that sparks a global alarm even more serious than the previously reported variants. Omicron has the capability to bypass at least some of the multi-faceted immune responses induced by prior infection or vaccination. It is shown to extensively escape neutralizing antibodies while evading cell mediated immune defense to a lesser extent. The efficacy of COVID 19 vaccines against Omicron variant is decreased with primary vaccination, showing that the vaccine is less efficient in preventing Omicron infections. However, after receiving a booster vaccine dose, the immunological response to Omicron significantly improved and hold promising results. Despite the mild nature of the disease in most vaccinated people, the rapid spread of Omicron, as well as the increased risk of re-infection, poses yet another major public health concern. Therefore, effort should be devoted to maintaining the existing COVID 19 preventive measures as well as developing new vaccination strategies in order to control the fast dissemination of Omicron.Keywords: Omicron variant, VOC, impact, COVID 19 vaccine efficacy, preventive strategies
