COVID-19 continues to spread rapidly around the world. Almost every country has reported cases, but the burden is asymmetrically distributed. In the past seven days (April 6–12), 46 percent of new confirmed cases have been reported in Europe, 39 percent in the United States and only 2% in The United Arab Emirates.

To an extent, that’s because countries are at different stages of the pandemic. Some that were effective at initial containment, such as United Arab Emirates. Singapore and Hong Kong, have seen resurgence and are implementing additional measures to address it.

Others, such as many countries in Western Europe, have seen the number of new cases plateau or begin to decline and are debating the right approach to reopening their economies. Some countries appear to be at the peak of infection and are urgently building surge capacity in their health systems. In other parts of the world, the number of cases is rising rapidly. Countries such as Russia and Turkey are seeing a recent acceleration. India too has experienced a significant increase in the number of cases since the beginning of April and has evolved its response strategy, including extending the nationwide lockdown.

Measures including physical distancing, travel restrictions, effective use of personal protective equipment (PPE), testing and tracing, and healthcare surge capacity require more or less emphasis, depending on epidemic phase and local context. Local use of these measures varies considerably—physical distancing may be near-impossible in crowded urban settings, for example, and the apps and digital tools for contact tracing like those used in China may not be acceptable in other parts of the world. Another challenge is the dependencies among these measures: to take one example, the timeliness and stringency of physical distancing measures substantially influences how other tools should be deployed.

The months ahead will probably be quite volatile and dynamic.

It now appears likely that some places will experience a local resurgence as restrictions are lifted and economies reopen. That will influence countries at the earliest stages. For example, UAE has seen a resurgence mainly from imported cases, which have led to local transmission; this suggests that restrictions on international travel may continue. As China gradually reopens, the tactics it used (including group-based isolation models and setting a norm of wearing masks in the workplace) and their efficacy will inform approaches around the world. Western Europe’s experience in relaxing restrictions, and the most successful approaches there, will inform the approaches deployed in the United States.

Considering the variety of approaches in use, public understanding and consensus will evolve day by day.

We will continue to find out more about the coronavirus—how it is mutating, the duration of immunity, its transmission dynamics, and so on.