Today in one sentence: Kamala Harris tested positive for Covid-19; the CDC estimates that nearly 60% of the U.S. population has Covid-19 antibodies due to past coronavirus infection; the Biden administration secured 20 million treatment courses of Pfizer's antiviral Covid-19 pill; Russian Foreign Minister Sergei Lavrov accused the West of pursuing a proxy war and warned there’s a “serious” risk of nuclear war over Ukraine; and a federal judge temporarily blocked the Biden administration from ending Trump-era pandemic restriction at the U.S.-Mexico border.

1/ Kamala Harris tested positive for Covid-19, making her the highest-ranking Biden administration official to report being infected. Harris received positive results on both rapid and PCR tests after returning from a weeklong trip to California, and “has exhibited no symptoms, will isolate and continue to work from the vice president’s residence,” according to spokeswoman Kirsten Allen. Harris isn’t considered a close contact of Biden (she was last with Biden on April 18 at the White House Easter egg roll). (CNN / Bloomberg / Washington Post / Politico / New York Times)

2/ The CDC estimates that nearly 60% of the U.S. population has Covid-19 antibodies due to past coronavirus infection. About 75% of U.S. children and teens have been infected – an increase of about 30 percentage points since December. The researchers examined more than 200,000 blood samples and found the presence of antibodies in 33.5% of Americans in December – when the Omicron wave began – which jumped to 57.7% in February. The seven-day average of new coronavirus cases was 47,029 on Monday – up from about 38,000 the week prior. (Politico / Bloomberg / Associated Press / New York Times / CNBC)

3/ The Biden administration secured 20 million treatment courses of Pfizer’s antiviral Covid-19 pill and plans to nearly double the number of pharmacies that carry the antiviral pills. Studies have shown that Paxlovid can reduce the risk of hospitalization or death by about 90% when taken within three to five days of the start of symptoms. Paxlovid is authorized for use in patients 12 and older who test positive for Covid-19 and are at a high risk for developing a severe case. (Washington Post / CNN / NPR / Wall Street Journal)

4/ Russian Foreign Minister Sergei Lavrov accused the West of pursuing a proxy war and warned there’s a “serious” risk of nuclear war over Ukraine. “The danger is serious, real. It can’t be underestimated,” Russia’s top diplomat said. U.S. Defense Secretary Lloyd Austin, speaking to reporters at Ramstein Air Base in Germany, said “any bluster about the possible use of nuclear weapons is dangerous and unhelpful.” Austin added that Putin “never imagined that the world would rally behind Ukraine so swiftly and surely.” The Biden administration, meanwhile, said that it supports Ukraine becoming a “neutral” nation in any possible peace deal. Secretary of State Antony Blinken, however, said there’s been “no sign to date” that Putin is serious about “meaningful negotiations.” (Bloomberg / Wall Street Journal / Washington Post / New York Times)

5/ A federal judge temporarily blocked the Biden administration from ending Trump-era pandemic restriction at the U.S.-Mexico border. The policy, known as Title 42, allowed U.S. immigration officials during the pandemic to quickly expel migrants without letting them seek asylum. Title 42 prevented more than 1.7 million attempts to cross the U.S. border since March 2020. The CDC announced in April that the policy would be rescinded on May 23. A suit brought by 21 Republican-led states, however, challenged the plan, claiming it would create a surge of migration from Mexico. On Monday, U.S. District Judge Robert Summerhays said he would grant a temporary restraining order blocking the end of Title 42. Summerhays was appointed by Trump. (The Hill / Politico / USA Today / CNN / CBS News / New York Times / NBC News)