The Contagious Nature of SARS-CoV-2 Omicron Variant and Vaccine Efficacy

Since the first coronavirus disease-19 (COVID-19) outbreak, variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have continued to dominate the global population. The repeated waves of emerging variants, each replacing the previous one with a greater rate of transmissibility and mutations, are the primary cause of the global pandemic. Public health concerns dramatically rose when a highly mutated variant, omicron (B.1.1.529) emerged in late 2021. Omicron has more than 50 mutations, and over 30 mutations are in their spike protein that contributes to the virologic characteristics of the variant. Omicron is more contagious than previously reported SARS-CoV-2 strains and can re-infect people who have already contracted other SARS-CoV-2 infections. The variant has acquired a unique immune escape mechanism against monoclonal antibodies and vaccines. Currently, there are no specific therapeutic drugs or vaccines available to prevent omicron infection and sub lineages emergence. The review was designed to search the recent research or literature papers and compile the most pertinent data on the virologic characteristics of the variant of concern. The study reviewed and discussed the present prevalence, infectivity, dominance, immune evasion, therapeutic options, vaccine efficacy, and the future prospect of the omicron variant. Omicron variant has become a global public health concern due to the emergence of highly mutated sub lineages. Developing variant-specific therapeutic drugs or vaccines is desirable to prevent the spread of these contagious variants globally.