Three phases of COVID-19: theoretical thinking on epidemic prevention and control

The response to the COVID-19 outbreak was evaluated by analyzing the literature published after the outbreak. By reviewing and summarizing the different stages, nodes and measures during the occurrence and development of COVID-19, other countries can draw on their experience and reference for the fight against COVID-19 in China. In December 2019, the COVID-19 was first reported in Wuhan, China, and then the whole world continued to pay close attention to the development of the COVID-19 in China. Until now, the outbreak and development of the COVID-19 has lasted for more than a year. Looking back on the process of the COVID-19, several key stages and events have had a profound impact on the development of the COVID-19. We divided the evolution of the outbreak since its origin into different phases. The policy changes of the Chinese government in different periods of the COVID-19 pandemic were evaluated, and the transformation nodes of the policies and differences in each stage were determined. We divided the evolution of the outbreak into three stages of the outbreak are initial outbreak stage, the carrying of the virus (people or goods) stage, and the non-direct contact transmission (goods transmission) stage. This paper reviews the three stages of the evolution of responses by the Chinese government to COVID-19 using a phase analysis method to examine different policy starting points, changes to policy, and reasons for policy change. The study provides a resource for COVID-19 policy review and includes image of the three-phase shift in policy as the epidemic progressed. By summarizing and describing the policy changes in the three phases of the response to COVID-19 in China, this paper provides a resource for others in formulating their response to the pandemic. The commentary is also designed to provoke scholarly dialog among the readers of the journal.