Johns Hopkins University

Margaret Keenan, a grandmother of four, made history Tuesday after getting a potentially lifesaving birthday present.

With one shot — or "jab" as Britons might say — Keenan, who turns 91 next week, officially launched the United Kingdom's nationwide coronavirus immunization campaign — the largest such effort in its history.

Updated Thursday at 11:20 a.m. ET

More than 100,000 Americans are in the hospital with COVID-19, at the same time the nation recorded its worst daily death toll since the start of the pandemic.

Data from the COVID Tracking Project show 100,226 people were hospitalized on Wednesday with the disease caused by the coronavirus — a figure that has been steadily rising for weeks.

Updated at 4:30 a.m. ET

The U.K. has formally approved Pfizer's coronavirus vaccine, becoming the first Western country to OK its use for the general public.

The British regulatory agency, the Medicines and Healthcare Products Regulatory Authority, or MHRA, announced early Wednesday the approval of the vaccine from Pfizer and the German company BioNTech for emergency use. The vaccine promises up to 95% protection against COVID-19, the disease caused by the coronavirus.

New coronavirus vaccines will help the world's economy bounce back in 2021, but the gains will depend on how the vaccines are distributed, among other factors, the Organisation for Economic Co-operation and Development says.

In its new projection, the group says global GDP should rise by 4.2% next year, after falling 4.2% in 2020.

The number of hospitalizations from the coronavirus set yet another record on Saturday, as cases continue to surge and public health officials warn of a worsening outlook with the holiday season just weeks away.

More than 91,500 people were hospitalized with the virus on Saturday, with 18,000 in intensive care units. That's according to data compiled by the COVID Tracking Project, which collects and analyzes data from across the United States. Over 6,000 patients were on ventilators.

As COVID-19 cases continue to surge across the nation, Los Angeles County has announced a new stay-at-home order that places new restrictions on businesses and gatherings but does not ban them altogether.

Friday's announcement came on a day when the number of new cases reached 205,000 nationwide — a figure believed to be higher, in part, due to delays in reporting caused by the Thanksgiving holiday. More than 4,500 of those cases were reported in Los Angeles County, along with 24 deaths.

Moncef Slaoui, the chief scientific adviser for Operation Warp Speed, says that some Americans could start receiving a COVID-19 vaccine by the second week of December.

The coronavirus pandemic is forcing the NCAA to scrap its traditional multi-city Division I Men's basketball tournament format in 2021. Instead, the NCAA plans to host all of March Madness in a single area in the spring, officials announced Monday.

The NCAA said it is holding talks with officials from the state of Indiana and the city of Indianapolis to host the 68-team tournament in March and early April.

More than 11 million confirmed coronavirus cases have been recorded in the United States, according to a COVID-19 tracker by Johns Hopkins University. The country reported 166,555 new cases on Sunday, with 1,266 new deaths.

Universal mask wearing in public could greatly reduce the number of Americans who die by COVID-19 by February, a study published Friday in the journal Nature Medicine projects.

Researchers at the University of Washington's Institute for Health Metrics and Evaluation made estimates based on some assumptions under different scenarios.