Former Vice President Joe Biden, Facebook CEO Mark Zuckerberg, and Coronavirus Response Coordinator Deborah Birx. Source: CNN

CNN’s Anderson Cooper and Dr. Sanjay Gupta hosted a global town hall on coronavirus with guests including former Vice President Joe Biden, Facebook CEO Mark Zuckerberg and Dr. Deborah Birx, the White House coronavirus response coordinator.

Here's what was discussed:

Testing and capacity: Birx said that it's important for states to match need with capacity as they ramp up widespread testing -- an important lesson learned during the HIV/AIDS crisis. When asked about widespread testing, she said it was unrealistic to expect that every worker in the US would get tested.

Guidelines to reopen the US: Birx said the guidelines issued by the White House today were “fairly strict" to give states the time to set up exactly how they’re going to contact trace. Testing, contact tracing and surveillance will need to be done as a partnership between the states, local leaders and the federal government, Birx said.

Social distancing measures: Dr. Chris Murray, the director of the Institute for Health Metrics and Evaluation at the University of Washington, said cell phone data anonymized and shared with his research team shows that people by and large are following social distancing policies.

Three steps to reopening: Dr. Leana Wen, the former health commissioner for the city of Baltimore, said that three things need to happen before economies and society can reopen safely:

Widespread testing capacity Infrastructure for contact tracing and surveillance A stabilized health care system

Economy vs health: Former US Vice President Joe Biden said it was a "false choice" to have to choose between the economy and peoples' health. Biden said it was important that small businesses stay open and said, "We should think about how we do the economy in a different way."

Opportunity to change mindsets: Biden said the way to get through the pandemic is to stimulate the economy and deal with the recovery. "And the way you deal with recovery is you think much bigger than we have before," he said. "I think we have an opportunity now to significantly change the mindset of the American people, things they weren't ready to do, you know, even two, three years ago."

Zuckerberg on Facebook: Facebook founder Mark Zuckerberg said employees of the social media giant will return to work in a staggered fashion and shouldn't expect to be back in their offices until at least the end of May. He also said the company will hold off on hosting "any internal or external physical events that have 50 people or more in them" through June of next year.