The Dawn is Coming —— the Description and Prediction of Omicron SARSCoV-2 Epidemic Outbreak in Shanghai by Mathematical Modeling

The COVID-19 Omicron outbreak in Shanghai has been going on for >1 month and 25 million population is subjected to strict lock-down quarantine. Until now, it is not clear how long this epidemic might end. Here, we present a time-delayed differentiation equation model to evaluate and forecast the spreading trend. Our model provides important parameters such as the average quarantine ratio, the detection interval from being infected to being tested positive, and the spreading coefficient to better understand the omicron progression. After data fitting, we concluded on 11 April that the maximum overall number infected in Shanghai would exceed 300,000 on 14 April and the turning point would be in the coming days around 13-15 April, 2022, which is perfectly in line with the real-life infection number. Furthermore, the quarantine ratio in Shanghai was found to be greater than 1, supportive of the effectiveness of the strict lockdown policy. Altogether, our mathematical model helps to define how COVID-19 epidemic progresses under the Shanghai lock-down unprecedented in human history and the Chinese zero tolerance policy.