Updated at 5:46 p.m. ET

President Biden announced Tuesday that his administration is working to purchase an additional 200 million doses of the two COVID-19 vaccines that have been authorized for emergency use, with the goal, the White House says, of having enough vaccine supply for the entire adult U.S. population by the end of the summer.

He also announced steps to increase vaccine doses going to state and local governments over the next three weeks, and to provide them more clarity going forward about how much supply they should expect.

Acting U.S. Capitol Police Chief Yogananda Pittman, in her first congressional testimony following the Jan. 6 assault on the Capitol, acknowledged her department's "failings" during the insurrection and said its members "fully expect to answer to you and the American people."

"I am here to offer my sincerest apologies on behalf of the Department," Pittman said.

Updated on Tuesday at 9:41 p.m. ET

A gorilla at the San Diego Zoo Safari Park in Escondido, Calif., underwent monoclonal antibody therapy after contracting COVID-19 this month.

Winston, an elderly silverback gorilla, and two other troop members tested positive for the coronavirus after they had symptoms such as mild coughing. "The virus was confirmed in 3 gorillas and we assume they all were exposed," Nadine Lamberski, the zoo's chief conservation and wildlife health officer, told NPR in an email. She said all the troop members were managed accordingly.

Karen Butcher's son Matthew struggled for years with an addiction to opioids. She's convinced the pandemic made it worse.

The restaurant in Scott County, Ky., where Matthew worked as a bartender closed before the pandemic, and soon other establishments, from restaurants to stores, followed suit as states imposed lockdowns.

"One day you're a bartender and you're serving people and having a great time at it, and then the next day the doors are closed," Butcher recalls. "Then COVID hits. It was the perfect storm."

With many U.S. schools still shuttered or operating on a limited basis, and millions of children learning remotely (or trying to), the stakes are high for Miguel Cardona. He is President Biden's pick to run the U.S.

Sixty-four years ago, residents of this tiny town in southwestern Kansas set a public health example by making it the first in the nation to be fully inoculated against polio.

It's a different story today.

People in Protection, like those in many rural communities, stand divided over how to slow the spread of the coronavirus and the safety of the vaccines being rolled out to protect them.