Comments on the Paper: "COVID-19: Data-Driven Dynamics, Statistical and Distributed Delay Models, and Observations" (Liu, X., Zheng, X., and Balachandran, B., 2020, Nonlinear Dyn., 101, pp. 1527-1543).

No doubt, the COVID-19 pandemic has been and is one of the greatest challenges of the mankind in its recent history. Though not unexpectedly, it has come abruptly. The reaction of the educated community has been abrupt, accordingly. Independent from the professional background, it must be said that almost everybody has a share in the global fight against the global consequences. It is not surprising, for example, when mechanical engineers have their own immediate contribution to satisfy the sudden extreme need in hospital equipment, the fast design and manufacturing of ventilators, test tools, to mention a few only. However, it is a welcome surprise when mechanicians and mechanical engineers have relevant and important comments on the underlying problem, the global spread of the virus. Actually, this article of Professor Bala Balachandran of the University of Maryland, College Park, MD, and his group represents just one... [ABSTRACT FROM AUTHOR]