The accumulation of more epidemiological data over the past 200 days has improved our collective understanding of the COVID-19 virus, as today we have improved models and a better understanding of the rates of asymptomatic carriers (estimated at 40%) and mortality rates (1.4%-15.4%). Yet still, uncertainties and local variability (even within countries) have made an accurate calculation of the COVID-19 basic reproductive number (R0; the number of people who are infected by a single disease carrier) difficult. In the early stage of the outbreak in Wuhan, R0 calculation ranged from 1.4-5.7, and some have suggested that instead of single R0 value, modellers should consider using ongoing contact tracing to gain a better range of transmissibility values.

We have seen how prevention strategies such as hand-washing, face-masking, and physical distancing can impact local and disseminated disease spread. While many communities have come together through a collective approach to lock-downs and universal masking measures, other localities have struggled to get adequate levels of citizen compliance. Others have struggled with obtaining testing supplies. Certain political systems allow for streamlined and unified directives while others have made it difficult to provide adequate centralized coordination.

As the COVID-19 pandemic has spread to almost every country in the world, outbreaks are smoldering in much of the global south. While the United States continues to see rising numbers of cases with numerous states confronting ongoing daily record high incident cases, other countries such as Brazil are seeing similar upward trends. At the global level, the curve of daily incident cases seemed to have “flattened” and held steady through much of April and into May with aggressive seemingly worldwide measures. However, since the last days of May, global incident cases have been again steadily increasing. This is likely due to a variety of reasons but is linked, at least in part, to efforts to reopen economies and return to pre-pandemic routines and lifestyles.