Will Omicron replace Delta?

But one of the reasons why we in the research community are particularly concerned is that the omicron variant has 10 mutations in the receptor-binding domain the part of the spike protein that interacts with the ACE-2 receptor and mediates entry into cells compared with just two for the delta variant. 

 Suppose the combination of all the mutations in omicron makes it either more transmissible or better at immune evasion than delta. In that case, we could see the spread of this variant globally. However, it is also possible that the unusually high number of mutations could be detrimental to the virus and make it unstable. It is highly likely that the omicron variant is not the endgame and that more SARS-CoV-2 variants will emerge. As SARS-CoV-2 continues to spread among humans, natural selection and adaptation will result in more variants that could plausibly be more transmissible than delta. We know from influenza viruses that the process of viral adaptation never ends. Lower vaccination rates among many countries means that there are still a lot of susceptible hosts out there for the virus, and that it will continue to circulate and mutate as long as it can spread. The emergence of the omicron variant is yet another reminder of the urgency to vaccinate to stop the further spread and evolution of SARS-CoV-2.