For months, the bulk of the United States' coronavirus cases were concentrated in the Northeast -- Massachusetts followed New York and New Jersey as the third-hardest-hit state in the nation.
But while those states have brought their outbreaks under control, this week outbreaks in the South and Southwest shot up. Florida and Texas were even forced to roll back some of their reopening measures.
Dr. Ashish Jha, who leads the Harvard Global Health Institute, said Saturday that that's down to reopening before critical testing infrastructure was put in place.
"This is happening because, in much of the country, around Memorial Day and the weeks that followed, we opened up while we still had a large number of cases," Jha said on "TODAY" in response to a chart showing the number of daily coronavirus cases resurging in the U.S. while remaining low in Europe.
The U.S. didn't install the kind of robust testing and contact tracing that public health experts were recommending when the initial shutdown measures were put into place, according to Jha.
"We opened up too fast. We opened up bars, we opened up nightclubs, and it's the combination of all of that that has led us to where we are today," he said.
He said it's been "frustrating because the shutdown was so painful," noting the millions of jobs that were lost and the time children have had to spend at home.
"I'm very worried we wasted that time as a country, our political leaders didn't do what needed to be done, and we're finding ourselves in a difficult situation now," he said.
He also cast some doubt on major sports leagues being able to restart, one bright spot for many Americans.
The NBA and MLS are planning to bring their teams down to Walt Disney World in Florida to hold games in a sealed-off environment, while MLB and the NHL are working out similar plans built around locations. But Florida is seeing record daily increases in cases -- nearly 9,000 on Friday alone -- and Jha said his advice for league commissioners is that it will only be safe to have games where there's no outbreak going on.
"It's going to be very, very hard to bubble off everbyody and make sure no one is affected," he said.
How Coronavirus Has Grown in Each State — in 1 Chart
This graph shows how the number of coronavirus cases have grown in Massachusetts, in the context of the other U.S. states, dating to the early days of the pandemic. It shows how many cases have been diagnosed each day in each state since their 500th cases. Select a state from the dropdown to highlight its track.
Source: The COVID Tracking Project
Credit: Amy O’Kruk/NBC
He also noted that, while the virus has so far seemed to kill mainly people in their 60s or older, its long-term health effects on people of all ages are unknown but potentially debilitating, and if he were an NBA player, he'd be worried about his longevity if he contracted the virus.