Bill Chappell

California is lifting stay-at-home orders for all regions in the state, including Southern California, the Bay Area and the San Joaquin Valley — the three regions that had still been under the order — citing a drop in intensive care unit projections. But health officials warn that most counties still need to follow strict guidelines.

Moderna says tests show that its COVID-19 vaccine offers protection against new variants of the coronavirus but that the vaccine is more effective against the variant first identified in the U.K. than the one found in South Africa. As a result, Moderna will test booster doses of its vaccine, including one that would be tailored to fight strains that have recently emerged.

Merck is halting development of its two COVID-19 vaccine candidates, saying that while the drugs seemed to be safe, they didn't generate enough of an immune response to effectively protect people against the coronavirus.

Updated at 3:10 p.m. ET

Hank Aaron, seen as a hero for shattering Babe Ruth's home run record and also for his longtime advocacy for civil rights, has died. "Hammerin' Hank" was 86. The Atlanta Braves confirmed his death on Friday.

A U.N. treaty outlawing nuclear weapons went into effect on Friday, having been ratified by at least 50 countries. But the ban is largely symbolic: The U.S. and the world's other nuclear powers have not signed the treaty.

"For the first time in history, nuclear weapons are going to be illegal in international law," Elayne Whyte, Costa Rica's former U.N. ambassador who oversaw the treaty's creation, tells NPR's Geoff Brumfiel.

Updated at 10:06 a.m. ET

"I am honored to announce that the United States will remain a member of the World Health Organization," Dr. Anthony Fauci said Thursday, informing the WHO's executive board that President Biden has reversed former President Donald Trump's move to leave the U.N.'s health agency.

The U.S. will also fulfill its financial obligations to the WHO, Fauci, chief medical adviser to the president, said, as well as cease a drawdown of U.S. staff who work with the organization.

Secretary of State Mike Pompeo is accusing China and its Communist Party of carrying out genocide against Muslim Uighurs and other minority groups in the western Xinjiang region in a forceful statement issued on Pompeo's last full day in his diplomatic role.

An art project that turned the border wall at the U.S.-Mexico border into the temporary base for pink seesaws – inviting children on each side to come play together – has won the London's Design Museum award for best design of 2020.

"We are totally surprised by this unexpected honor," said Ronald Rael, who designed the project with fellow architect Virginia San Fratello. They share the award, he said, with the Ciudad Juárez, Mexico-based art collective Colectivo Chopeke.

President-elect Joe Biden is nominating Pennsylvania health expert Dr. Rachel Levine to be assistant secretary for health in the department of Health and Human Services, in a move that could make Levine the first openly transgender federal official to win Senate confirmation.

Levine is currently the secretary of health in Pennsylvania, where she leads the state's fight against COVID-19. She is also professor at the Penn State College of Medicine. Levine began her medical career as a pediatrician at Mount Sinai Medical Center in New York.

Updated at 11:45 a.m. ET

Rebekah Jones, the data scientist who helped create Florida's COVID-19 dashboard, has turned herself in to police, in response to an arrest warrant issued by the state.

Jones is charged with one count of "offenses against users of computers, computer systems, computer networks and electronic devices," the Florida Department of Law Enforcement said in a statement Monday.