UK Prime Minister Boris Johnson announced a stricter "tier 4" lockdown for London and southeast England on Saturday, citing a rapidly spreading new strain of COVID-19 detected by government scientists. 

The new strain was not more dangerous, he stressed during a press briefing, but it was spreading faster, particularly in London and southeast England. The new variant may be 70% more transmissible than any strain previously detected, he said. There is no evidence a vaccine is less effective against it, he added.

The new restrictions go into effect Sunday morning. People are encouraged to stay home, and only one household indoors and two households outdoors will be allowed.

Previously, up to three households could gather from Dec. 23-27.

“We cannot continue with Christmas as planned," Johnson said Saturday.

All nonessential shops, sports facilities and gyms will also close.  

The restrictions will last at least two weeks.

-ABC News' Mike Trew contributed to this report

FedEx Express, a subsidiary of FedEx Corp said Saturday it "operations were in motion" to transport the Moderna COVID-19 vaccines for McKesson Corp. throughout the United States.

FedEx Express will begin transport of the vaccine and kits of supplies for administration of the vaccine, using its FedEx Priority Overnight service supported by FedEx Priority Alert advanced monitoring, the company said in its statement.

-Ahmad Hemingway, Anne Flaherty, Stephanie Ebbs, Sophie Tatum, Arielle Mitropoulos and Ivan Pereira

The United States reported a record high of 249,709 new COVID-19 cases Friday -- just shy of a quarter-million -- according to updated data compiled by Johns Hopkins University. 

Also, according to The COVID Tracking Project's Friday evening update, a record 114,751 people were hospitalized with the coronavirus, marking the thirteenth straight day that the nation has hit a record high of current hospitalizations.

Additionally, 2,814 deaths were reported Friday, according to Johns Hopkins University. 

By all metrics, this week has been the worse since the pandemic began in terms of COVID-19 cases, hospitalizations and deaths.

Stanford Medical Center has apologized for its vaccine plan that left out many front-line doctors following Friday's protest. 

In a statement obtained by KGO, Stanford Health Care wrote: "We take complete responsibility for the errors in the execution of our vaccine distribution plan. Our intent was to develop an ethical and equitable process for distribution of the vaccine. We apologize to our entire community, including our residents, fellows, and other frontline care providers, who have performed heroically during our pandemic response. We are immediately revising our plan to better sequence the distribution of the vaccine."

On Friday morning, hundreds of residents protested at Stanford Medical Center, saying that only seven front-line residents were going to be given the COVID-19 vaccine in the first wave of 5,000 vaccines the hospital was allocated. 

Front-line doctors at the protest said orthopedic surgeons, dermatologists and telehealth doctors were getting vaccinated before them.

California Department of Public Health spokesperson Ali Bay also released a statement following the protest. 

"The federal and state vaccine guidelines have prioritized our front-line health care workers who have been putting their lives at risk to fight this virus from day one. We urge all health care providers to follow the state's guidelines on vaccination phases which were created in consultation with experts and community leaders," Bay said.