Coronavirus updates: Herd immunity by fall 'ambitious,' says surgeon general nominee

American pharmaceutical firm Eli Lilly and Company released new data showing that a laboratory-made protein delivered by infusion may help prevent COVID-19 infections at nursing homes. 

A phase 3 trial found that nursing home residents who got the monoclonal antibody drug were 80% less likely to develop symptomatic COVID-19 compared to nursing home residents who got a placebo infusion. 

Among all the study participants (including residents and staff), those who got the drug were 57% less likely to develop symptomatic COVID-19.

The Eli Lilly drug, called bamlanivimab, has FDA emergency authorization to treat people already sick with COVID-19 who might need to be hospitalized. The company says it will work with regulators to potentially expand this authorization to include nursing home residents and staff to help prevent outbreaks.

The U.S. Centers for Disease Control and Prevention advises that those who’ve had monoclonal antibody treatment wait 90 days until getting a COVID-19 vaccine.

ABC News’ Sony Salzman and Dr. Mishal Reja contributed to this report.

In hard-hit California, the daily number of new COVID-19 cases fell below 20,000 on Wednesday, while the number of COVID-19 patients in hospitals is also on the decline, California’s Secretary of Health and Human Services, Dr. Mark Ghaly, told ABC's "GMA3: What You Need To Know."

Ghaly attributed the progress to "the ongoing work of Californians to pay attention to the virus."

"After what was a hard Thanksgiving holiday, I think the regional stay-at-home order that the governor put in place made a difference over the winter holidays," Ghaly said. "We're starting to see that pay off now."

"Almost to the day, three weeks after putting [stay-at-home orders] into place in some of the hardest hit areas, we started to see the numbers come down," he added.

The state's stay-at-home orders are enacted when a region's intensive care unit capacity falls below 15%. Stay-at-home orders are currently in effect in three of the state's five regions: Southern California, the Bay Area and the San Joaquin Valley.

COVID-19 vaccinations are also ramping up.

"The governor gave us a million-vaccine challenge over 10 days that ended last week," Ghaly said. "And we saw a radical increase going from about 40,000-47,000 vaccines given in a day at the beginning of that challenge to over 110,000 vaccines given a day across the state."

California, which has a population of 39.5 million people, has the highest tally of confirmed COVID-19 cases of any U.S. state, with over 3 million patients diagnosed, according to a count kept by Johns Hopkins University.

Glastonbury Festival, the largest greenfield music festival in the world, has been canceled for the second year in a row due to the coronavirus pandemic.

"With great regret, we must announce that this year’s Glastonbury Festival will not take place, and that this will be another enforced fallow year for us," the festival's organizers, Michael and Emily Eavis, said in a statement Thursday. "In spite of our efforts to move Heaven & Earth, it has become clear that we simply will not be able to make the Festival happen this year. We are so sorry to let you all down."

The world-famous event typically takes place over the course of five days on the organizers' dairy farm in the village of Pilton in southwest England, with star-studded lineups that attract around 200,000 attendees each year. Last year's festival, the 50th anniversary with Paul McCartney due to headline, was also canceled because of the pandemic.

"As with last year, we would like to offer all those who secured a ticket in October 2019 the opportunity to roll their £50 deposit over to next year, and guarantee the chance to buy a ticket for Glastonbury 2022," the organizers said. "We are very appreciative of the faith and trust placed in us by those of you with deposits, and we are very confident we can deliver something really special for us all in 2022!"

South African President Cyril Ramaphosa announced Thursday that one of the ministers in his cabinet has died from COVID-19.

Jackson Mthembu, minister in the presidency, died earlier Thursday from complications related to the disease, according to Ramaphosa. He was 62.

"Minister Mthembu was an exemplary leader, an activist and life-long champion of freedom and democracy," Ramaphosa said in a statement. "He was a much-loved and greatly respected colleague and comrade, whose passing leaves our nation at a loss."

Mthembu played a prominent role in South Africa's COVID-19 response and was often the public face during press briefings. He had announced via Twitter on Jan. 11 that he tested positive for COVID-19.

Since the start of the pandemic, South Africa has confirmed more than 1.3 million cases of COVID-19, including at least 38,854 deaths. The country has the highest tally of confirmed cases in Africa, accounting for 41% of the continent's diagnosed infections, according to the latest data from the Africa Centers for Disease Control and Prevention.