...SARS-CoV-2 could mutate at an unsteady pace. Supportive evidence comes from the accelerated evolution which was revealed by tracking mutation rates of the genomic location of Spike protein. This process is sponsored by a small portion of the virus population but not the largest viral clades.
We found that the new variants carrying advantageous mutations could not be instantaneously dominant but has to experience a selection in a large population for 1 to 6 months. This course varies in the continents, indicating its relations with other factors, such as isolation policy, population size, and control policy (masking, distancing, and travel constriction). This may be also related to the transmissibility of the emerging variants
Through gaining new mutations and surviving from the high selection pressure, current variants had the ability to spread more quickly in population (3, 6, 21), evade detection by specific diagnostic tests (27), and potentially evade natural or vaccine-induced immunity (8, 12, 28). Thus, the model could answer the question why cases and deaths were still increasing while people have been receiving vaccines: SARS-CoV-2 has been experiencing a second evolutionary acceleration since October 2020 and current variants such as B.1.1.7 already succeed selection thus would possibly reach a peak around July 2021.
Moreover, it generally took one to six months for current variants that caused peaks of COVID-19 cases and deaths to survive selection pressure. Based on this statistic result and the above speedy Spike evolution, another upcoming peak would come around July 2021 and disastrously attack Africa, Asia, Europe, and North America. This is the prediction generated by a mathematical model on evolutionary spread. The reliability of this model and future trends out of it comes from the comprehensive consideration of factors mainly including mutation rate, selection course, and spreading speed.