Emergence of novel omicron hybrid variants: BA(x), XE, XD, XF more than just alphabets

Emergence of novel omicron hybrid variants: BA(x), XE, XD, XF more than just alphabets The continuous evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) since 2019 created numerous variants like Alpha, Beta, Gamma, Delta, Theta, Lambda, Mu, and finally, Omicron which emerged in November 2021.Viruses are known to create mutations by accumulating errors during viral replications, resulting in emergence of new variants.The Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) designated Delta (B.1.617.2) and Omicron (B.1.1.529)variants as 'currently circulating Variants of Concern' (VOCs) due to their increased transmissibility and virulence in clinical disease presentation [1].Further computational analysis of the Omicron variant shows distinct sublineages namely BA.1 (B.1.1.529.1),BA.2 (B.1.1.529.2),BA.3 (B.1.1.529.3),BA.4, and BA.5 (Fig. 1), all were detected in South Africa indicating their fast evolutionary divergence.The World Health Organization (WHO) prioritizes monitoring of BA.2.12.1, BA.2.9.1, BA.2.11, BA.2.13, BA.4, and BA.5 sublineages that may pose a threat to global health and require attention and categorize them under VOC lineages under monitoring (VOC-LUM).A large number of genomic mutations as 50 in BA.1, 51 in BA.2, and 43 in BA.3 is the most worrisome attribute of Omicron which may be a matter of concern for public health.As of May 19, 2022, Omicron extended to 187 countries, and around 3.7 million sequences have been submitted in GISAID with a maximum from the United Kingdom (UK, 1,152,917), followed by the United States of America (USA, 1,003,940) [2].Accounting for >99.9% of total submitted viral genomic sequences, Omicron is now dominating around the world.Additionally, the emergence of Deltacron hybrids also worsened the current pandemic situation.