ABSTRACT
Omicron, the new ‘Variant of Concern’ of SARS-CoV-2, is rapidly evolving into new sub-variants or sub-lineages (BA.1, BA.2 etc.). These sub-variants have higher transmissibility, decreased vaccine effectiveness and increased risk of reinfection. As a result, many nations across the globe are reporting surge in infections which is a matter of concern. 
Understanding Omicron and its sub-variants is vital for development of public health policy and preventing disease transmission. The present paper throws a spotlight on the newly detected sub-variants of Omicron as reported in ongoing researches which are available only in pre-print form and also the importance of a booster dose of the vaccine. Information regarding recent research on a new nasal vaccine formulation, which may be effective against the new variants, is also highlighted in the paper.