COVID-19 live updates: 'Extremely unlikely' virus came from Chinese lab, WHO says

Hospitalizations for COVID-19 in California have fallen 34% over the past two weeks, Gov. Gavin Newsom said at a Monday press conference at Petco Park in San Diego, which has been turned into a mass vaccination site.

A month ago, the Golden State was logging more than 50,000 newly confirmed cases of COVID-19 each day. On Monday, the daily figure fell to 10,414 while the average testing positivity rate was at 5%, down from 14% last month, according to Newsom.

"Hopeful signs continue," the governor wrote on Twitter Monday.

ABC News' Bonnie Mclean and Alex Stone contributed to this report.

More than 117,000 confirmed cases of COVID-19 among children were reported in the United States last week, representing a 10% increase in cases between Jan. 21 and Feb. 4, according to a report released Monday by the American Academy of Pediatrics and the Children's Hospital Association.

The report, which compiles state-by-state data on infections among kids, found that 2.9 million children have tested positive for COVID-19 nationwide since the start of the pandemic. In total, children represent 12.9% of all cases in U.S. states that report COVID-19 data by age.

ABC News' Arielle Mitropoulos contributed to this report.

Facebook announced Monday a global campaign to promote authoritative COVID-19 sources and push back on disinformation.

The effort will including helping people find out where and when to get vaccinated, expanding the social media company's efforts to remove false COVID-19 information from Facebook and Instagram, and giving $120 million in advertising credits to health ministries, NGOs and UN agencies.

Facebook also said it would provide data for education to help build trust in COVID-19 vaccines, as well as to inform vaccine delivery efforts.

ABC News' Mary Kathryn Burke contributed to this report.

Ten percent of Americans, or 31.6 million people, have received one or more doses of the COVID-19 vaccine, according to a U.S. Department of Health and Human Services planning document obtained by ABC News.

Three percent of the population, or 9.1 million people, have gotten both shots of the two-dose vaccine, according to the document.

U.S. President Joe Biden has pledged to get 100 million shots into Americans' arms during the first 100 days of his presidency. Since his Jan. 20 inauguration, 24.6 million doses have been administered.

ABC News' Josh Margolin and Brian Hartman contributed to this report.