Omicron variant of SARS-CoV-2: A review of existing literature

Abstract

On November 24th, 2021 a case of a new viral variant of SARS-CoV-2 was reported by South Africa and Botswana to WHO, which later was designated as the variant of concern on 26th November 2021. It has around 60 mutations (50 non synonymous, 8 synonymous, and 2 non coding) as compared to the original parent strain of Wuhan. Different hypotheses have been put forward as an explanation for the origin like reverse zoonosis i.e. animal to human transmission, origin from an immune compromised patient or use of highly mutagenic drug like molnupiravir as treatment. A huge spike in cases around the globe is suggestive of a high rate of infectivity and transmissivity as compared to the previous known variants. With whatever cases have been documented so far, it is said that omicron causes mostly mild clinical illnesses and there is a less chance of hospitalization according to the clinicians. Among the reported cases, there were already vaccinated patients also. So there is a possibility that omicron might be able to evade the vaccine induced immunity due to a huge number of mutations (especially in the spike protein sequences). Until new vaccines specific to the pathogen are being developed, the coverage of the currently acceptable vaccines should be increased so that none is deprived of the mandatory doses and a third booster dose might help to reduce the chances of serious complications of this new strain beforehand. So an equal focus on the host and environment is required along with the pathogen.