Health Care Policy Makers’ Response to COVID-19 Pandemic; Pros and Cons of “Flattening the Curve” from the “Selective Pressure” Point of View: A Review

Covid-19, a respiratory infection caused by the virus sars-cov-2, causes a variety of symptoms in infected people. we have recently addressed our concerns over unintentional “directed accelerated evolution” of the sars-cov-2 and introduced a modified treatment method for ards associated with covid-19. covid-19 outbreak could last for a long time in communities. due to growing requests for medical equipment such as ventilators and icu beds, “flattening the epidemic curve” has been considered as an effective strategy to adjust the level of health care demand to potential capacity of the system. in this paper, we compare possible outcomes of “without precaution” and “with precaution” epidemic models. when there are no precautions, a higher number of people would be infected. rna viruses such as sars-cov-2 have extremely high mutation rates. accordingly, the combination of a higher number of infected people and any effort for inactivation of the viruses is expected to exert a strong selective pressure on sars-cov-2 that can lead to more mutations. these mutations can be either pathogenicity attenuating mutations (pams) or pathogenicity promoting mutations (ppms). on the other hand, when flattening strategy is used, the number of infected people will be lower than the previous model, but both type of mutations may occur, although with lower frequency. although the occurrence of pams helps the development of herd immunity, possible occurrence of ppms needs serious tracking, especially in patients with severe covid-19, to prevent new endemic with more virulent mutant viruses.