The Discovery of SARS-Cov2 Variant Omicron and concern Tony Qu, Grade 11 Crescent School, Sunlifegene Academic Program in Medical Science SLAP COVID 19 Research Program Toronto, ON, Canada December 20, 2021

On 26 November, the newly emerged variant Omicron was designated a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern. On November 19 scientists at the Botswana Harvard HIV Reference Laboratory Dr Sikhulile Moyo and his team first discovered the variant Omicron( https://www.thecrimson.com/article/2021/12/6/harvard-botswana-lab-omicron/)The Omicron variant was also discovered at Lancet Laboratories in Pretoria, South Africa. However, that does not necessarily confine the origin of the variant to South Africa because the country’s well-designed genetic surveillance system makes it prone to the discoveries of new variants.

 Different from previous variants of concern (Alpha, Beta, Gama, and Delta), Omicron displayed far more mutations in its genome. In the spike protein, the new variant had 30 mutations compared to the original viral strain from Wuhan. As seen in the Alpha and Delta variants, mutated spike protein allows the virus to be more transmissible and more likely to evade the immune system and vaccine. The Omicron variant also shares the P681H mutation with the Alpha variant, which affects the proteolytic cleavage site at the junction of the spike protein receptor-binding (S1) and fusion (S2) domains. Moreover, the combination of Q498R and N501Y mutations allows more effective binding of the virus to the angiotensin converting enzyme 2 (ACE2) receptors, thus promoting viral entry into human cells. Fortunately, 80% of epitopes in the spike protein recognized by CD8+ T cells are not affected by the mutations in the Omicron variant, so vaccines still grant a certain level of protection to people. 

In an experiment, scientists found that Omicron replicated around 70 times more than the Delta variant and the original SARS-CoV-2 virus over 24 hours, but it did not replicate in the lung tissue as well as the bronchus tissue.

 These findings are well-reflected in the real world as the omicron variant is more infectious but less severe compared to other variants.Ontario was reporting less than 3100 cases on Dec 18,2021; even since Omicron came to Ontario, the province began reporting more than 1000. As of December 14, 1808 cases of SARS-CoV-2 were reported.  In South Africa, which is the region that Omicron has affected the most, patients infected by the new variant have a 29% lower risk of being hospitalized. And across the world, relatively less omicron patients are admitted to the ICU.