What we know about the Omicron, a new variant of SARS-CoV2 Keva Garg G11 Student at the University of Toronto Schools SunLifegene Academic Program in Medical Science Dec 20,2021

Two years since the emergence of the SARS-CoV-2 pandemic, multiple variants of the virus have emerged such as Alpha, Beta, Gamma and Delta variants. However, compared to previous SARS-CoV-2 variants, Omicron, a new variant, has exhibited an even higher degree of mutation. It is speculated that the variant transmits faster than previous variants as it multiplies and infects the human bronchus. Nevertheless, it does not infect the lower lungs easily, which, according to researchers, might explain the proportionally lower incidence of severe disease in omicron cases. Omicron has both novel mutations that haven't been seen before, as well as a higher likelihood of spreading than other variants. Lawrence Young, a virologist and professor of molecular oncology at Warwick Medical School, said, “This variant carries some changes we’ve seen previously in other variants but never altogether in one virus. It also has novel mutations that we’ve not seen before.” There are more than 50 mutations in the variant's genome, including more than 30 in the spike protein, which has been targeted as a primary target for current vaccines. Using lung tissue to isolate the Omicron SARS-CoV-2 variant, it was compared with the original SARS-CoV-2 and the Delta variant. In comparison to Delta and the original SARS-CoV-2 virus, Omicron replicated roughly 70 times more quickly in human brochium over 24 hours. On the other hand, Omicron expressed lower replication levels in the lung tissue (more than 10 times lower) than the original virus. Despite this, there are still many risks with this novel variant such that the rate at which people are fed into the healthcare system (particularly the unvaccinated) increases, which makes it harder for the healthcare system to cope. Furthermore, disease severity is determined not only by virus replication, but also by host immunity, which can result in dysregulation of the innate immune system or excessive amounts of cytokines in the bloodstream.