对人类流动性和流行病学数据的分析表明，新冠病毒流行病的早期和晚期，旅行限制是最有用的。

COVID-19: Travel restrictions are most useful in the early and late phase of an epidemic

https://www.sciencedaily.com/releases/2020/03/200325110842.htm

Journal Reference:

1. Moritz U. G. Kraemer, Chia-Hung Yang, Bernardo Gutierrez, Chieh-Hsi Wu, Brennan Klein, David M. Pigott, Open Covid- Data Working Group†, Louis Du Plessis, Nuno R. Faria, Ruoran Li, William P. Hanage, John S. Brownstein, Maylis Layan, Alessandro Vespignani, Huaiyu Tian, Christopher Dye, Oliver G. Pybus, Samuel V. Scarpino. The effect of human mobility and control measures on the COVID-19 epidemic in China. Science, 2020 DOI: 10.1126/science.abb4218