1. Introduction
The COVID-19 pandemic, the biggest public health crisis in a century has
caused an estimated 476 million cases and 6.1 million deaths till date
globally. [1]
During the pandemic, multiple variants of SARS-CoV-2 have emerged that
have been found to vary in transmissibility and severity. Omicron
(B.1.1.529) variant has emerged after Alpha, Beta, Gamma and Delta
SARS-CoV-2 variants, during November 2021 as a highly mutated virus
variant, classified as variant of concern (VOC) by WHO on 26 November
2021, that has now attained the position of a dominant strain in several
countries owing to its very high transmissibility [2]. With the
emergence of the Omicron (B.1.1.529) variant of SARS-CoV-2, there is
remarkable decrease in the disease severity relative to previous
variants such as Delta (B.1.617.2). The lower disease severity seen in
populations during the Omicron wave of the SARS-CoV-2 pandemic infection
[3] can be attributed to changes in the virus that limit its ability
to spread in the lungs and, probably most importantly, to increased
immunity in the population from previous SARS-CoV-2 infection and
vaccination [4]. In the last 6 months cases of COVID 19 are
declining [1]. It seems that, the disease is going towards
endemicity.
The patients infected with Omicron variant have shorter hospital stay,
lesser number of patients receiving intensive care, and fewer deaths
than delta variant. Though presenting as low severity disease, its
higher transmissibility might present a threat for co-morbid patients
[2].
The present study deals with comparison of morbidity and mortality with
SARS-CoV-2 Omicron (B.1.1.529) and Delta (B.1.617.2) variants.