Medical people around the world are trying hard to get that to below 1.0, whereupon diseases stop spreading. Those who are social distancing are helping to drive that down. It is intriguing that he started his graph precisely when closings and social distancing orders started.

What is plotted is the effective R, not the R₀ as commonly discussed -- which is the transmissibility number in a 100% susceptible population with no precautions taken.