Coronavirus lockdown measures put into place in six countries prevented more than 500 million additional COVID-19 infections, including tens of millions in the United States, a new study has concluded.

A study published in Nature on Monday and conducted by University of California at Berkeley researchers found that measures implemented to slow the spread of the coronavirus in the United States prevented 60 million infections up to April 6, The Washington Post reports.

The study looked at six countries and found that various shutdown policies and interventions prevented or delayed 530 million infections across the United States, China, South Korea, Italy, Iran, and France, though the researchers say 62 million of the additional infections would have actually been officially confirmed as cases through testing, including 4.8 million confirmed cases in the U.S. The United States has confirmed about 1.9 million COVID-19 cases.

In China, 285 million cases were prevented, the study says, with this including 37 million cases that would have been confirmed. The researchers looked at the effect of 1,717 policies put into place to slow the virus' spread in these countries.

"I don't think any human endeavor has ever saved so many lives in such a short period of time," lead author Solomon Hsiang said. "There have been huge personal costs to staying home and canceling events, but the data show that each day made a profound difference. By using science and cooperating, we changed the course of history." Brendan Morrow

Seven states are teaming up with the goal of expanding rapid COVID-19 testing.

The governors of Maryland, Louisiana, Massachusetts, Michigan, Ohio, Virginia, and North Carolina have announced an interstate compact "to expand the use of rapid point-of-care antigen tests" during the coronavirus pandemic. The bipartisan group of governors is in talks to buy 500,000 antigen tests for each state.

"By banding together, the states are demonstrating to private manufacturers that there is significant demand to scale up the production of these tests, which deliver results in 15-20 minutes," the announcement said, touting this as the first such interstate testing agreement during the pandemic.

The compact was negotiated by Maryland Gov. Larry Hogan (R), who on Tuesday thanked "my fellow governors for signing on to this groundbreaking bipartisan agreement" to "acquire millions of faster tests to help save lives and slow the spread of COVID-19," adding that "we will be working to bring additional states, cities, and local governments on board as this initiative moves forward." Brendan Morrow

President Trump phoned into Fox & Friends on Wednesday morning and, as he's wont to do, took some shots at his predecessor, former President Barack Obama.

Co-host Brian Kilmeade asked Trump to comment on Obama's eulogy at last week's funeral for the late civil rights leader Rep. John Lewis, which Kilmeade said reminded him of a "campaign speech" rather than a eulogy. Trump appeared to agree, adding that it was a "terrible speech" and a supposedly "angry" Obama "lost control" while speaking. The president also claimed Obama's words received criticism from "both sides."

Trump then meandered away from the eulogy and began talking about how his administration has "redone" a very specific 82 percent of very unspecific "Obama things" seemingly related to environmental policy. Watch the clip below. Tim O'Donnell

Former Vice President Joe Biden could be down to two contenders in his search for a running mate.

A new report from Axios details how Biden confidants believe he has narrowed his list down to Sen. Kamala Harris (D-Calif.) and former National Security Adviser Susan Rice. While the report cautions that things could change, it notes that these confidants "would be surprised if he picks anyone else."

As far as Harris goes, Axios writes that Biden's brain trust has "deep and trusting relationships" with those who are pushing for the California senator while touting her skills as a prosecutor. But on the other hand, according to the report, Rice is "getting a big bounce" from former President Barack Obama's alumni, who say that picking her would "guarantee the enthusiastic presence" of Obama and former first lady Michelle Obama on the campaign trail.

Other possible contenders include Rep. Karen Bass (D-Calif.), who the report says is in third place behind Harris and Rice, as well as Sen. Elizabeth Warren (D-Mass.) and Sen. Tammy Duckworth (D-Ill.). The Washington Post previously reported that Biden was expected to interview five or six finalists but that there was a sense that he still doesn't have "a clear favorite."

Though Biden had previously said he intended to make his running mate pick in the first week of August, the announcement is no longer expected to come until next week, prior to the Democratic National Convention's start on Aug. 17. Read more at Axios. Brendan Morrow

In a stunning victory, progressive activist Cori Bush defeated Rep. William Lacy Clay in Missouri's 1st Congressional District Democratic primary on Tuesday.

Clay has represented the district for the last 20 years, and before that, his father, William Lacy Clay Sr., held the seat for three decades. Bush ran against the incumbent in 2018, but lost by a 20-point margin. On Tuesday, with 100 percent of precincts reporting, Bush has 48.6 percent of the vote, compared to Clay with 45.5 percent.

Bush was endorsed by Sen. Bernie Sanders (I-Vt.), and is calling for universal health care, raising the minimum wage, and police reform. In a victory speech, Bush said Missouri's 1st Congressional District "has decided that an incremental approach isn't going to work any longer. We decided that we the people have the answers, and we will lead from the front lines." Catherine Garcia

Voters in Missouri on Tuesday approved a ballot measure expanding Medicaid to roughly 230,000 low-income residents.

With 99 percent of precincts reporting, 53 percent voted "yes" on the measure, while 47 percent voted "no." Missouri is the sixth red state to expand Medicaid, and the second to do so amid the coronavirus pandemic, after Oklahoma. The state is now reporting on average more than 1,200 daily new coronavirus cases, nearly three times more than a month ago, Politico reports.

Missouri has until July 1, 2021, to expand Medicaid under the Affordable Care Act. The measure amends the state's constitution, so lawmakers cannot add requirements to the program. Gov. Mike Parson (R) opposed the expansion, saying it was too expensive and the state doesn't have enough money to pay for it. The federal government gives states up to 90 percent of funding necessary for Medicaid expansion, an improvement over the 65 percent provided to Missouri now under its current program.

"Quite frankly, Missourians are sick and tired of not getting their fair share," Jack Cardetti, a spokesman for the ballot initiative's organizers, told Politico last week "They pay their taxes, they've seen now 37 other states use that money to expand access to health care. Meanwhile, our economy's clearly ailing here." Catherine Garcia

To raise money for cancer research, Andrew Walker and Jacob Adkins traded in their ice skates for rollerblades and hit the road.

Walker and Adkins are hockey players at the University of Massachusetts Boston. They wanted to do something during the pandemic to help others, and came up with a way to raise money and awareness for the American Cancer Society: the roommates would rollerblade from Boston to Mason, Michigan, a nearly 900-mile journey.

Cancer has affected both of them personally, with Adkins' mother in remission after being diagnosed with Hodgkin's lymphoma and Walker's grandfather dying of the disease. Adkins and Walker — who dubbed themselves the Men in Blades — completed their trek in 10 days, arriving in Mason late last month. They raised $28,100, a feat they are especially proud of since donations to so many charities are down because of the pandemic.

"This experience has humbled both of us and has made us just that much more grateful for the people around us and that much more loving," Adkins told WHDH. Catherine Garcia