COVID-19 updates: Anti-vaccine protesters halt vaccinations at Dodger Stadium

British Prime Minister Boris Johnson has indicated that England's lockdown restrictions will remain in place until at least early March.

In a statement to lawmakers at the U.K. House of Commons on Wednesday, Johnson said officials "do not yet have enough data to know exactly how soon it will be safe to reopen our society and economy." But he expressed hope that schools could reopen from March 8, so long as his government meets its target of vaccinating everyone in the top four priority groups by mid-February.

The prime minister also announced new restrictions for travelers arriving in England from countries deemed to be high-risk. He said the United Kingdom remains in a "perilous situation" with more than 37,000 people hospitalized with COVID-19 -- almost double the amount during the previous peak in April.

During a press conference later Wednesday, Johnson told reporters that March 8 was the "earliest" date by which the government could "responsibly" allow schoolchildren to return to classrooms.

The comments come after the U.K. became the fifth country in the world to record more than 100,000 deaths from COVID-19.

England entered its third national lockdown of the coronavirus pandemic on Jan. 5.

Although Johnson is the prime minister of the U.K., his administration is only responsible for COVID-19 restrictions in England because public health legislation is devolved to national governments within the U.K., meaning that Scotland, Wales and Northern Ireland are responsible for their own coronavirus-related policies.

A new, more contagious variant of the novel coronavirus first identified in the United Kingdom has been detected in Alabama for the first time.

The Alabama Department of Public Health announced Wednesday that two cases of the variant were confirmed in Montgomery County residents and a third in a Jefferson County resident. Two of the patients are children under the age of 19.

"These are the first reported cases in Alabama of the variant which was first detected in the United Kingdom in late 2020," the department said in a statement. "This variant is associated with increased person-to-person transmission of COVID-19. ADPH is closely monitoring the emergence of this variant which has been detected in at least 24 other states."

The so-called B117 variant, which is believed to have emerged in England in September, has been detected in more than two dozen U.S. states.

The U.S. Centers for Disease Control and Prevention now projects that the country will have recorded up to 514,000 COVID-19 deaths by Feb. 20.

The CDC on Wednesday published its latest national ensemble forecast, which predicts that the country's COVID-19 death rate will likely decrease over the next four weeks and that 13,500 to 25,000 new fatalities from the disease will likely be reported in the week ending Feb. 20. A total of 479,000 to 514,000 COVID-19 deaths are projected to be reported nationwide by this date.

Last week’s national ensemble forecast predicted there would be a total of 465,000 to 508,000 COVID-19 deaths reported nationwide by Feb. 13.

ABC News' Ahmad Hemingway contributed to this report.

The United States has detected at least 315 confirmed cases of the highly contagious variant of the novel coronavirus that first emerged in the United Kingdom, according to the latest data from the Centers for Disease Control and Prevention.

California and Florida are tied at 92 cases each for the U.S. state with the most confirmed cases of the so-called B117 variant, according to CDC data.

The variant was first identified in England in September and has since spread to dozens of other countries around the world.

ABC News' Ahmad Hemingway contributed to this report.